Long-Chain Ketimine Synthesis in a Gold−Thallium Polymer

pubs.acs.org/OrganometallicsPublished on Web 06/10/2010r 2010 American Chemical Society

Organometallics 2010, 29, 2951–2959 2951

DOI: 10.1021/om100188f

Long-Chain Ketimine Synthesis in a Gold-Thallium Polymer

Eduardo J. Fern�andez,† Alessandra Garau,§ Antonio Laguna,‡ Tania Lasanta,†

Vito Lippolis,§ Jos�e M. L�opez-de-Luzuriaga,*,† Manuel Montiel,† and M. Elena Olmos†

†Departamento de Quımica, Universidad de la Rioja, Grupo de Sıntesis Quımica de La Rioja, UA-CSIC,Complejo Cientıfico Tecnol�ogico, 26001 Logro~no, Spain, ‡Departamento de Quımica Inorg�anica,

Instituto de Ciencia de Materiales de Arag�on, Universidad de Zaragoza-CSIC, 50009 Zaragoza, Spain, and§Dipartimento di Chimica Inorganica edAnalitica,Universit�a degli Studi di Cagliari, S.S. 554Bivio per Sestu,

09042 Monserrato (CA), Italy

Received March 10, 2010

The heteropolynuclear complex [Tl{Au(C6Cl5)2}]n reacts with sterically demanding diamines as tetra-methylenediamine (TMDA), 2,20-(ethylenedioxy)bis(ethylamine) (NOON), or triethylenetetramine (trien)in 1:1 molar ratio in tetrahydrofuran (THF), leading to products of stoichiometry [Tl{Au(C6Cl5)2}(L)]n(L=TMDA(1),NOON (2), or trien (3)) or [Tl2{Au(C6Cl5)2}2(L)]n (L=trien (4)) when the solvent used istoluene. Addition of acetylacetone to the diamine complexes in 1:1 molar ratio generates [Tl{Au-(C6Cl5)2}{OdC(CH3)CHC(CH3)NH(CH2)4NH2}]n (5) and in 1:2 molar ratio [Tl{Au(C6Cl5)2}(L

x)]n(Lx = {OdC(CH3)CHC(CH3)NHCH2CH2}2 (6), {OdC(CH3)CHC(CH3)NHCH2CH2OCH2}2 (7)).When the molar ratio is 1:2, with the exception of 3, all these complexes display luminescence in the solidstate at room temperature and at 77K. The origin of the luminescence could be assigned to a delocalizatedexciton along the heterometallic chain formed byAu 3 3 3Tl interactions. In addition, a red shift is observedwhen the temperature decreases, which is attributed to the shortening of the Au-Tl distance at lowertemperatures. The emissive properties of solutions of 5-7 and [Tl{Au(C6Cl5)2}]n inTHFwere studied afteradding increasingamountsofdifferentmetal ions (Zn2þ,Cd2þ,Hg2þ, Pb2þ,Cu2þ,Al3þ,Ni2þ,Agþ,Mn2þ,Bi3þ) and anions (F-, Cl-, Br-, I-, H2PO4

-, ClO4-, Bz-, Ac-, HSO4

-, NO3-). Interestingly, an

enhancement of the fluorescence emission intensity was observed for the complexes considered only uponaddition of Br-, Cl-, and Ac-.

Introduction

In the last years the chemistry of heteropolynuclear ex-tended linear-chain compounds built by secondary interac-tions has renewed physicists’ and chemists’ interest due to thespecial characteristics of their bonding and the physical andchemical properties associated with these systems.1,2 In fact,heterometallic systems have been considered very promisingcandidates for photophysical studies3 that could lead to theiruse as light-emitting devices or even VOC sensors.4-11

Nevertheless, the use of these materials as frameworks uponwhich organic reactions can be carried out in order to synthe-size unknown derivatives or known products whose experi-mental conditions for their synthesis should be improved is apromising but unexplored area. In this sense, our grouprecently described the easy ketimine formation in the coordina-tion sphere of the thallium atom of compounds of formula[AuTlR2(en)] (R=C6F5, C6Cl5; en = ethylenediamine).12,13

In our previous reports, the coordinated ethylenediaminereacted with acetone or acetophenone12 or cyclic ketones ascyclopentanone, cyclohexanone,or cycloheptanone,13givingrisetomono-ordiketimines coordinated to the thalliumcenters.Thereactions occurred in very fast and smooth conditions, at roomtemperature and in solution or in solid-gas phase. This resultcontrasts with the classical synthesis of ketimines by azeotropicdistillation, which required high temperatures, prolonged reac-tion periods, and the presence of dehydrating agents.14-17 Veryinterestingly, when those experiments were carried out in theabsence of one of the metal centers, i.e., gold or thallium, the

*To whom correspondence should be addressed. E-mail: [email protected].(1) Hoffmann, R. Angew. Chem., Int. Ed. Engl. 1987, 26, 846.(2) Williams, J. M.; Schultz, A. J.; Underhill, A. E.; Carneiro, K. In

ExtendedLinearChainCompounds; PlenumPress:NewYork, 1982;Vols. 1-3.(3) Fern�andez, E. J.; Laguna, A.; L�opez-de-Luzuriaga, J. M. Gold

Bull. 2001, 34, 14-19, and references therein.(4) Beauvais, L. G.; Shores, M. P.; Long, J. R. J. Am. Chem. Soc.

2000, 122, 2763.(5) Buss, C. E.; Mann, K. R. J. Am. Chem. Soc. 2002, 124, 1031.(6) Cariati, E.; Bu, X.; Ford, P. C. Chem. Mater. 2000, 12, 3385.(7) Dias, H. V.; Divabalalage, H. V.; Rawashded-Omary,M; Franzman,

M. A.; Omary, M. A. J. Am. Chem. Soc. 2003, 125, 12072.(8) Evju, J. K.; Mann, K. R. Chem. Mater. 1999, 11, 1425.(9) Fern�andez, E. J.; L�opez-de-Luzuriaga, J. M.;Monge,M.; Olmos,

M. E.; P�erez, J.; Laguna, A.; Mohamed, A. A.; Fackler, J. P., Jr. J. Am.Chem. Soc. 2003, 125, 2022.(10) Fern�andez, E. J.; L�opez-de-Luzuriaga, J. M.; Monge, M.; Montiel,

M.; Olmos,M. E.; P�erez, J.; Laguna, A.;Mendiz�abal, F.; Mohamed, A. A.;Fackler, J. P., Jr. Inorg. Chem. 2004, 43, 3573.(11) Mansour, M. A.; Connick, W. B.; Lachicotte, R. J.; Gysling,

H. J.; Eisenberg, R. J. Am. Chem. Soc. 1998, 120, 1329.

(12) Fern�andez, E. J.; Laguna, A.; L�opez-de-Luzuriaga, J. M.; Montiel,M.; Olmos, M. E.; P�erez, J.Organometallics 2006, 25, 1689.

(13) Fern�andez, E. J.; Laguna, A.; Lasanta, T; L�opez-de-Luzuriaga,J. M.; Montiel, M.; Olmos, M. E. Inorg. Chim. Acta 2010, 363, 1965.

(14) Taguchi, K.; Wesheimer, F. H. J. Org. Chem. 1971, 58, 556.(15) Love, B. E.; Ren, J. J. Org. Chem. 1993, 58, 556.(16) Look, G. C.; Murphy, M. M.; Campbell, D. A.; Gallop, M. A.

Tetrahedron Lett. 1995, 36, 2937.(17) Vaas, R. S.; Duda’s, J.; Varma, R. S.Tetrahedron 1999, 40, 4951.

2952 Organometallics, Vol. 29, No. 13, 2010 Fern�andez et al.

reactions did not lead to the imines’ formation. Consideringthese results, we assumed that the cooperative interaction of thegold and thallium centers in the chains was responsible for thisbehavior, and as a consequence, both the electronic demand ofthallium(I) and the low occupancy of the coordination sphere ofthis atomwere the key factors in the success of these reactions. Intheprevious studies,while theacceptor abilitiesof theketonehadinfluence in the stoichiometry of the reactions,12 the sterichindrance of the substituents seemed not to have an influenceon the rate of transformation of the starting ethylenediaminematerial into the final products.13

Goingonwith this study,wehavenow tested the reactivity ofthe starting gold/thallium compound with different stericallydemanding diamines and a longer ketone to simultaneouslystudy the influence of the amine and ketone size in the forma-tion of the imines. Therefore, in this paper we report thereactivity of [Tl{Au(C6Cl5)2}]nwith diamines, as tetramethyle-nediamine, 2,20-(ethylenedioxy)bis(ethylamine), or triethylene-tetramine, and the reactivity of the resulting compounds withacetylacetone, studying in addition the optical changes asso-ciated with these reactions.

Results and Discussion

Synthesis andCharacterization.Compounds [Tl{Au(C6Cl5)2}-(L)]n (L=tetramethylenediamine (TMDA) (1), 2,20-(ethylenedi-oxy)bis(ethylamine) (NOON) (2), and triethylenetetramine(trien) (3)) are obtained by reaction of [Tl{Au(C6Cl5)2}]n andequimolecular amounts of the different diamines, using tetrahy-drofuranas solvent.However, theuseof toluene leads to the sameproducts in the case of diamines TMDA and NOON, whe-reas for trien a compound of stoichiometry [Tl2{Au(C6Cl5)2}2-(L)]n (L=trien (4)),withahighermetallic content, isobtained(seeScheme 1). In addition, a transformation from [Tl{Au(C6Cl5)2}-(trien)]n (3) into [Tl2{Au(C6Cl5)2}2(trien)]n (4) occurs by treatinga suspension of 3 in toluene or dichloromethane (see Scheme 1).

These products are isolated as orange (1, 4), yellow (2), orwhite (3) solids and are insoluble in solvents with low coordi-nating capability, such as dichloromethane, toluene, acetoni-trile, or diethyl ether, and partially soluble in tetrahydrofuran.They are stable to air and moisture for long periods of time.

Analytical and spectroscopic data of complexes 1-4 agreewith the proposed stoichiometries (see Experimental Section).

Their IR spectra show, among others, absorptions at 839-831and 614-607 cm-1 arising from the presence of a pentachlor-ophenyl group bonded to gold(I) and at 3383-3200 cm-1 dueto N-H stretching modes. Mass spectra (ES-) show signalscorresponding to [Au(C6Cl5)2]

- atm/z=695with the expectedisotopic distributions, but other peaks of higher nuclearity arenot detected.

The 1H NMR spectra of complexes 1-4 indicate the pre-sence of diamines linked to thallium, as the patterns for theinequivalent hydrogen atoms appear at different shifts from theones described for the corresponding free ligands. Thus, these1HNMRspectra inTHF-D8display signals at 2.64 (CH2a) and1.41 ppm (CH2b) (1); 3.59 (OCH2 c), 3.45 (OCH2b), and 2.86ppm (CH2a) (2); 2.75 (CH2a), 2.70 (NHCH2 c), and 2.59 ppm(NHCH2b) (3); 2.82 (CH2a), 2.77 (NHCH2 c), and 2.70 ppm(NHCH2b) (4) (see Scheme 2), while the spectra of the freediamines show signals at 2.70 (CH2a) and 1.45 ppm (CH2b)(TMDA), 3.65 (OCH2 c), 3.46 (OCH2b), and 2.78 ppm (CH2a)(NOON), or 2.70 (CH2a), 2.60 (NHCH2 c), and 2.35 ppm(NHCH2 b) (trien).

Treatment of [Tl{Au(C6Cl5)2}(TMDA)]n (1) with an equi-molecular amount of acetylacetone leads to the formationof [Tl{Au(C6Cl5)2}(L

1)]n (L1 = {OdC(CH3)CHC(CH3)NH-

(CH2)4NH2}) (5) (see Scheme 3), while [Tl{Au(C6Cl5)2}(L2)]n

(L2={OdC(CH3)CHC(CH3)NHCH2CH2}2) (6) is obtainedwhen a 1:2 molar ratio or an excess of acetylacetone isemployed (see Scheme 3).

Complexes 5 and 6 are isolated as yellow solids, and they areinsoluble in solvents such as dichloromethane, toluene, acetoni-trile, or acetone and partially soluble in tetrahydrofuran. Ana-lytical and spectroscopic data of both complexes agree with theproposed stoichiometries (see Experimental Section). Their IRspectra show, among others, absorptions at∼3600 cm-1 arisingfrom thepresenceof hydrogenbondsbetweenN-Hgroups andoxygen18 andat 1605-1505 cm-1 due toCdO,CdC,andCdN

Scheme 1 Scheme 2

Scheme 3

(18) €Ozkar, S.; Ulk€u, D.; Yıldırım, L. T.; Biricik, N.; G€umg€um, B.J. Mol. Struct. 2004, 688, 207.

Article Organometallics, Vol. 29, No. 13, 2010 2953

stretching modes. In addtion, in 5 there is an absorption at3271 cm-1 due to N-H stretching modes.

The low solubility of complex 5 in usual solvents preventsits 1H NMR characterization. However, the 1H NMRspectrum of complex 6 indicates the presence of six differenttypes of protons in the ligand (L2 in Scheme 4): olefinicprotons (x) at 4.89 ppm, methylenic protons at 3.28 (c) and1.29 ppm (d), and methylic protons at 1.90 (a) and 1.85 ppm(b). In addition, a broad signal at 10.88 ppm confirms thepresence of hydrogen bonds (z) between nitrogen andoxygenatoms in the ligand (see Scheme 4).18

Treatment of [Tl{Au(C6Cl5)2}(NOON)]n (2) with acetylace-tone in 1:2 molar ratio leads to the formation of [Tl{Au-(C6Cl5)2}(L

3)]n (L3 = {OdC(CH3)CHC(CH3)NHCH2CH2O-

CH2}2) (7). However, when the reaction takes place with anequimolecular amount of acetylacetone, a mixture of 7 andunreacted 2 is obtained.

Complex 7 is isolated as a yellow solid, stable to air andmoisture. It is partially soluble in tetrahydrofuran andinsoluble in dichloromethane, toluene, or acetonitrile. Ana-lytical and spectroscopic data of 7 agree with the proposedstoichiometry (see Experimental Section). Its IR spectrumshows, among others, absorptions at 833 and 612 cm-1

arising from the presence of a pentachlorophenyl groupbonded to gold(I), at 1600 and 1533 cm-1 due to CdO andCdN stretching modes, respectively, and other signals at∼3600 cm-1 assigned to hydrogen bonds. The presence ofthese hydrogen atoms (z) is also confirmed in its 1H NMRspectrum in THF-D8, which displays a resonance at 10.83ppm. In addition, there are signals corresponding to olefinicprotons (x) at 4.91 ppm, methylenic protons at 3.63 (e), 3.61(d), and 3.40 ppm (c), and methylic protons at 1.95 (a) and1.90 ppm (b) (see Scheme 4).

However, contrary to the results observed in the previousstudies,12,13 complexes 1-4 in the solid state do not reactwith ketone vapors at room temperature, probably due to thepresence of sterically demanding diamines.Crystal Structures. Single crystals of compounds 1,

4 3 toluene, 6, and 7 suitable for X-ray diffraction studieswere obtained by slow diffusion on n-hexane into a solutionof the complex in tetrahydrofuran (1, 6, and 7) or toluene(4 3 toluene). All these structures display polymeric chains ofalternating [Au(C6Cl5)2]

- and [Tl(L)]þ units linked via un-supported Au 3 3 3Tl interactions, which run parallel to thecrystallographic x (4 3 toluene and 7) or y (1 and 6) axis. Thepresence of bridging bidentate N-donor ligands in the caseof complexes 1 and 4 3 toluene results in the expansion ofthe infinite chains in a second dimension, giving rise to2D networks (see Figures 1 and 2), while in the structuresof 6 and 7 the O-donor ligands bonded to thallium act as

bidentate chelating, thus affording 1D polymers (Figures 3and 4).

With the exception of one of the Au 3 3 3Tl distances foundin 6, of 3.5763(4) A, which is the longest one described to date(close to the sumof van derWaals radii for gold and thallium

Scheme 4

Figure 1. Crystal structure of complex 1. Hydrogen atoms havebeen omitted for clarity.

Figure 2. Crystal structure of complex 4 3 toluene. Hydrogenatoms have been omitted for clarity.



of 3.62 A), the Au 3 3 3Tl distances in these structures varyfrom 2.9782(4) to 3.1047(4) A (see Tables 2-5) and are similarto those observed in other related polynuclear Au/Tl sys-tems with unsupported metal-metal interactions (2.9078(3)-3.3205(3) A).9,10,19-27 In the structures of complexes 1,4 3 toluene, and 7 the gold(I) centers (except Au(2) in 4 3 toluene)display a perfect square-planar environment, taking into ac-count the Au 3 3 3Tl contacts, since these atoms lie in the inver-sion centers. Although this stereochemistrywith covalent bondsis unusual for Au(I), it is common in extended systems built viametal-metal interactions.28 In contrast, in compound 6 thegeometry at gold is more distorted, with Tl-Au-Tl andC-Au-C bond angles of 131.326(11)� and 177.2(3)�, respec-tively. The Au-C bonds show typical lengths, ranging from2.027(7) A in 6 to 2.081(9) A in 1.

In complexes 1 and 4 3 toluene, each thallium binds twonitrogen atoms, although with different strength, and thus,the geometry at thallium, also considering the intermetallic

contacts, is distorted trigonal bipyramidal with the goldcenters occupying the apical positions and the stereochemicallyactive lone pair in the vacant equatorial coordination site. Themaindifference betweenboth structures is thatwhile in 1 there isone amine (TMDA) per thallium and each nitrogen bonded tothallium belongs to a different TMDA, which acts as bidentatebridging ligand, in the case of 4 3 toluene there is half an amine(NOON) per thalliumatomandbothnitrogenatomsbonded tothalliumbelong to the sameNOONmolecule, which behaves astetradentate chelating and bridging ligand. The Tl-Ndistancesrange from 2.660(8) to 2.905(18) A, the shorter ones being simi-lar to those found in the related gold-thallium amine-imine ordiimine compounds [AuTl(C6F5)2(Me2CdNCH2CH2NH2)]nor [AuTl(C6X5)2(Me2CdNCH2CH2NdCMe2)]n (X = F, Cl)(2.520(6)-2.694(9) A),12 while the upper extreme represents thelongest Tl-N distance found in these types of systems.

The geometry at thallium in the crystal structures of 6 and 7

is also distorted trigonal bipyramidal considering the Au 3 3 3Tlcontacts with a vacant equatorial coordination site apparentlyassociated with the stereochemically active lone pair and thegold centers occupying the apical positions (Au-Tl-Auangles 131.326(11)� and 141.686(13)�, respectively). Each thal-lium is bonded to two oxygen atoms of one bidentate chelatingligand, thus forming a 14- (6) or 19-membered ring (7), withsimilar Tl-O bond distances of 2.607(6) and 2.617(6) A in 6


Table 1. Data Collection and Structure Refinement Details for Complexes 1, 4 3 toluene, 6, and 7

1 4 3 toluene 6 7

chemical formula C16H12AuCl10N2Tl C30H18Au2Cl20N4Tl2 3C7H8 C26H24AuCl10N2O2Tl C28H28AuCl10N2O4Tlcryst habit orange needle red prism yellow prism yellow prismcryst size/mm 0.35 � 0.15 � 0.05 0.2 � 0.1 � 0.1 0.2 � 0.2 � 0.1 0.2 � 0.08 � 0.08cryst syst triclinic monoclinic monoclinic triclinicspace group P1 P21/c P21/a P1a/A 9.4367(2) 15.3243(3) 10.5447(2) 11.4964(2)b/A 11.9611(4) 22.6272(5) 12.0192(2) 12.8560(3)c/A 11.9970(4) 16.9930(4) 26.9038(5) 15.1920(4)R/deg 100.531(2) 90 90 105.2870(10)β/deg 94.162(2) 112.110(1) 90.956(1) 103.5070(1)γ/deg 110.0370(10) 90 90 111.5170(8)U/A3 1237.28(6) 5459.0(2) 4819.83(11) 1873.53(7)Z 2 4 4 2Dc/g cm-3 2.652 2.480 2.245 2.149M 984.08 2038.29 1152.31 1212.36F(000) 904 3744 2160 1144T/�C -100 -100 -50 -1002θmax/deg 61 55 56 56μ(Μo KR)/mm-1 13.515 12.257 9.832 8.955no. of reflns mead 24 113 64 378 27 443 29 877no. of unique reflns 7484 12 189 8039 8851Rint 0.0683 0.082 0.0810 0.0922Ra (I>2σ(I)) 0.0579 0.0510 0.0540 0.0596wRb (F2, all reflns) 0.1564 0.1364 0.1454 0.1611no. of params 274 590 383 418no. of restraints 40 77 40 40Sc 1.007 1.040 0.991 0.996max. ΔF/e A-3 3.538 2.230 2.629 3.277

a R(F)=P

)Fo|- |Fc )/P

|Fo|.b wR(F2)= [

P{w(Fo

2- Fc2)2}/

P{w(Fo

2)2}]0.5;w-1= σ2(Fo2)þ (aP)2þ bP, whereP=[Fo

2þ 2Fc2]/3 and a and b are

constants adjusted by the program. c S = [P

{w(Fo2 - Fc

2)2}/(n - p)]0.5, where n is the number of data and p the number of parameters

Table 2. Selected Bond Lengths [A] and Angles [deg] for Complex 1a

Tl-N(1) 2.654(10) Au(2)-C(11) 2.082(8)Tl-N(2)#1 2.905(18) Tl-Au(1) 2.9782(4)Au(1)-C(1) 2.058(8) Tl-Au(2) 3.0929(4)N(1)-Tl-N(2)#1 84.9(5) Tl-Au(1)-Tl#2 180.0Au(1)-Tl-Au(2) 160.176(16) C(11)#3-Au(2)-C(11) 180.0(3)C(1)#2-Au(1)-C(1) 180.000(1) Tl-Au(2)-Tl#3 180.000(15)

a Symmetry transformations used to generate equivalent atoms:#1 -x, -y, -z; #2 -xþ1, -yþ1, -z; #3 -xþ1, -y, -z.


and 2.575(7) and 2.626(7) A in 7. These distances are very closeto those described for the polymeric complex [AuTl(C6Cl5)2-(acacH)2]n, which contains acetylacetone as ligand (2.626(8)and 2.692(9) A),10 and compare well with most of the Tl-Obond lengths found in other related polymeric Au/Tl systemscontaining O-donor ligands, which vary from 2.471(3) to2.890(3) A10,19-22 and from which the shortest distances arethose that involve aOdPPh3 ligand. In the case of both 6 and 7the presenceof two intramolecularN-H 3 3 3Ohydrogenbondsper ligand gives rise to six-membered planar rings (seeFigures 5

and 6 andTables 6 and 7), similar to those previously describedin the related Au/Tl compounds [Au2Tl2(C6Cl5)4] 3 (acacH)29

and [Au2Tl2(C6Cl5)4(acacH)2]n.10 It is worth noting that both

rings in 6 or one of them in 7 is nearly parallel to the per-chlorophenyl groups and displays distances between the cen-troids of the C6Cl5 and OC3NH rings of 3.479 and 4.196 A (6)or 3.646 A (7). Interactionsbetween cloudsofπ electrondensity

Table 3. Selected Bond Lengths [A] and Angles [deg] for Complex

4 3 toluenea

Au(1)-C(1) 2.050(7) Au(2)-Tl(1) 3.0520(4)

Au(2)-C(11) 2.069(8) Au(3)-Tl(2) 3.0645(3)

Au(2)-C(21) 2.048(8) Tl(1)-N(1) 2.680(9)

Au(3)-C(31) 2.063(7) Tl(1)-N(2) 2.693(10)

Au(1)-Tl(1) 2.9852(3) Tl(2)-N(3) 2.793(11)

Au(2)-Tl(2) 2.9826(4) Tl(2)-N(4) 2.660(8)

C(1)#1-Au(1)-C(1) 180.0 Tl(2)-Au(3)-Tl(2)#2 180.0

Tl(1)#1-Au(1)-Tl(1) 180.0 N(1)-Tl(1)-N(2) 66.2(3)

C(21)-Au(2)-C(11) 178.9(4) Au(1)-Tl(1)-Au(2) 160.904(15)

Tl(2)-Au(2)-Tl(1) 169.020(15) N(4)-Tl(2)-N(3) 66.2(3)

C(31)-Au(3)-C(31)#2 180.0 Au(2)-Tl(2)-Au(3) 128.366(14)

a Symmetry transformations used to generate equivalent atoms:#1 -xþ1, -yþ2, -z; #2 -xþ1, -yþ1, -z.

Table 4. Selected BondLengths [A] andAngles [deg] for Complex 6a

Tl-O(2) 2.607(6) Au-C(11) 2.037(8)Tl-O(1) 2.617(6) Tl-Au 3.1047(4)Au-C(1) 2.027(7) Tl-Au#1 3.5763(4)O(2)-Tl-O(1) 81.8(2) C(1)-Au-C(11) 177.2(3)Au-Tl-Au#1 123.548(11) Tl-Au-Tl#2 131.326(11)

a Symmetry transformations used to generate equivalent atoms:#1 x-1/2, -yþ3/2, z; #2 xþ1/2, -yþ3/2, z.

Table 5. Selected Bond Lengths [A] and Angles [deg] for Complex 7a

Au(1)-C(1) 2.062(8) Au(2)-Tl 3.0134(3)Au(2)-C(11) 2.078(8) Tl-O(41) 2.575(7)Au(1)-Tl 3.0717(3) Tl-O(20) 2.626(7)C(1)#1-Au(1)-C(1) 180.0 Tl#2-Au(2)-Tl 180.0Tl#1-Au(1)-Tl 180.0 O(41)-Tl-O(20) 67.1(2)C(11)#2-Au(2)-C(11) 180.0 Au(2)-Tl-Au(1) 141.686(13)

a Symmetry transformations used to generate equivalent atoms:#1 -xþ1, -y, -z; #2 -xþ2, -y, -z.

Figure 5. Asymmetric unit of complex 6 (30% probability level)with the labeling scheme of the atom positions. Hydrogen atoms(except those involved in H-bonds) have been omitted for clarity.

Figure 6. Asymmetric unit of complex 7 (30% probability level)with the labeling scheme of the atom positions. Hydrogen atoms(except those involved in H-bonds) have been omitted for clarity.

Table 6. Hydrogen Bond Lengths [A] and Angles [deg] forComplex 6

D-H 3 3 3A d(D-H) d(H 3 3 3A) d(D 3 3 3A) — (DHA)

N(1)-H(1) 3 3 3O(1) 0.86 2.02 2.696(9) 134.5N(2)-H(2) 3 3 3O(2) 0.86 2.00 2.672(9) 134.7

Table 7. Hydrogen Bond Lengths [A] and Angles [deg] forComplex 7

D-H 3 3 3A d(D-H) d(H 3 3 3A) d(D 3 3 3A) — (DHA)

N(26)-H(26) 3 3 3O(20) 0.86 1.99 2.669(12) 135.5N(35)-H(35) 3 3 3O(41) 0.86 1.94 2.621(11) 135.8

(19) Fern�andez, E. J.; Laguna, A.; L�opez-de-Luzuriaga, J. M.; Monge,M.; Montiel, M.; Olmos, M. E.; P�erez, J.Organometallics 2004, 23, 774.(20) Crespo, O.; Fern�andez, E. J.; Jones, P. G.; Laguna, A.; L�opez-

de-Luzuriaga, J. M.; Mendıa, A.; Monge, M.; Olmos, M. E. Chem.Commun. 1998, 2233.(21) Fern�andez, E. J.; Laguna, A.; L�opez-de-Luzuriaga, J. M.; Montiel,

M.; Olmos, M. E.; P�erez, J. Inorg. Chim. Acta 2005, 358, 4293.(22) Fern�andez, E. J.; Laguna, A.; L�opez-de-Luzuriaga, J. M.;

Mendiz�abal, F.; Monge, M.; Olmos, M. E.; P�erez, J. Chem.;Eur. J.2003, 9, 456.(23) Fern�andez, E. J.; Laguna, A.; L�opez-de-Luzuriaga, J. M.;

Montiel, M.; Olmos, M. E.; P�erez, J. Organometallics 2005, 24, 1631.(24) Fern�andez, E. J.; Laguna, A.; L�opez-de-Luzuriaga, J. M.; Olmos,

M. E.; P�erez, J.Dalton Trans. 2004, 1801.(25) Fern�andez, E. J.; Jones, P. G.; Laguna, A.; L�opez-de-Luzuriaga,

J. M.; Monge, M.; Montiel, M.; Olmos, M. E.; P�erez, J. Z. Naturforsch.2004, 59b, 1379.(26) Fern�andez, E. J.; Jones, P. G.; Laguna, A.; L�opez-de-Luzuriaga,

J. M.; Monge, M.; Olmos, M. E.; P�erez, J. Inorg. Chem. 2002, 41, 1056.(27) Fern�andez, E. J.; Laguna, A.; Lasanta, T.; L�opez-de-Luzuriaga,

J. M.; Montiel, M.; Olmos, M. E. Organometallics 2008, 27, 2971.(28) Fern�andez, E. J.; Laguna, A.; L�opez-de-Luzuriaga, J.M.Coord.

Chem. Rev. 2005, 249, 1423.(29) Fern�andez, E. J.; L�opez-de-Luzuriaga, J. M.; Olmos, M. E.;

P�erez, J.; Laguna, A.; Laguna, M. C. Inorg. Chem. 2005, 44, 6012.


of neighboring, nearly parallel aromatic rings that lead tointercentroid distances of about or below 3.5 A are consideredas effective π 3 3 3π interactions,30 so both complexes show acertain degree of weakπ 3 3 3π interaction, which is evenweakerin the case of complex 7.Optical Properties. Complexes 1, 2, and 4, obtained by

treatment of the heteropolimeric chain [Tl{Au(C6Cl5)2}]nwith different diamines (TMDA, NOON, and trien, respec-tively), and compounds 5-7, derived from their reactionwith acetylacetone, are luminescent in the solid state at roomtemperature and at 77 K, as shown in Table 8.

The UV-vis spectra of these seven compounds in THFsolutionpresent similar features (seeTable 1S in theSupportingInformation): an intense band at around 220 nm followed by abroad band in the range 290-300 nm. For complexes 1-4 theband at higher energy appears roughly at the same wavelengthas in the free diamines, and therefore, we suggest a similarorigin, probably a nfσ* transition in the C-N bonds. At thispoint, it is important to note that in the absorption spectra ofthe precursor complex [AuTl(C6Cl5)2] a low-energy band at250 nm also appears and, therefore, both transitions wouldappear masked. In the case of the gold precursor NBu4[Au-(C6Cl5)2], the absorption spectrum shows a band at 290 nm,which is assigned to ππ* transitions in the pentachlorophenylrings.28 This band also appears in complex [AuTl(C6Cl5)2], andthus, we propose for the low-energy band in the complexes asimilar assignment. In the case of complexes 5-7 the spectrashow similar features with an additional shoulder at 258 nmthat we assign to transitions in the imine groups.

The excitation spectra in the solid state show bands atlower energies than those previously presented, a fact thatcould be related to the absence of metal-metal interactions

in solution. Thus, similarly to the reported examples of poly-meric heterometallic gold-thallium chains,28 the origin of theluminescence could be assigned to a delocalizated exciton alongthe heterometallic chain formedbyAu 3 3 3Tl interactions.How-ever, complex 3 does not show luminescence in the solid state,and the absence of its molecular structure prevents confirmingthe existence of these interactions.

The lifetimes of these complexes in the solid state at roomtemperature are on the order of nanoseconds (see Table 8) andclose to those described for similar [Tl{Au(C6Cl5)2}(L)]n com-pounds, which could be in accordance with fluorescent pro-cesses.10 Nevertheless, the foreseeable strong spin-orbit cou-pling does not allow us to ensure this assumption. Complexes 1,2, and 4 show a unique emission at room temperature and at77 K, which is independent of the excitation wavelength. Inaddition, a red shift is observed when the temperature decreases(seeFigures 7and8),which is usual for this kindof extended sys-tems10,20,25,26,31,32 and is attributed to the shortening of theAu-Tl distance at lower temperatures as a consequence of the ther-mal contraction. The same situation is observed for compounds5-7, inwhich the excitationwavelengthgoes from350 to500nm(see Figures 9 and 10). In addition, the emission spectra ofsome of the complexes (1, 4, and 7) show a vibrational structurein the solid state at 77 K, which is indicative of the contribution

Figure 7. Excitation and emission spectra for 1 (left) and 2 (right).

Table 8

solida lifetime

complex RT 77 K ns χ2

1 625(510) 680(510) 1784, 359 2.812 545 (480) 560 (490) 433, 115 0.624 630 (480) 640 (480-530) 2368, 290 2.595 605 (495) 605 (480) 292, 71 2.616 570 (370-470) 620 (475) 357, 60 1.007 540 (480) 570 (430) 855, 166 4.43

aWavelength (nm). In parentheses λ excitation.

Figure 8. Excitation and emission spectra for 4.

(30) Olmos, M. E. In Supramolecular Architecture by SecondaryBonds in Modern Supramolecular Gold Chemistry; Laguna, A., Ed.;Wiley-VCH: Weinheim, 2008; pp 337-341, and references therein.

(31) Wang, S.; Garz�on, G.; King, C.; Wang, J. C.; Fackler, J. P., Jr.Inorg. Chem. 1989, 28, 4623.

(32) Wang, S.; Fackler, J. P., Jr.; King, C.; Wang, J. C. J. Am. Chem.Soc. 1988, 110, 3308.


of the ligands to the excited state responsible for the emission.Nevertheless, the poor definition at that temperature does notallow us to identify the responsible mode.

All the complexes considered lose the Au 3 3 3Tl interactionsin tetrahydrofuran solution and, consequently, their lumines-cence properties, according to what has already been observedfor other heterometallic gold(I)-thallium(I) complexes.28 Aswe have stated, these complexes are not soluble in dichloro-methane, toluene, acetonitrile, etc., which prevents us fromstudying the stability of the interactions in those solvents. Inaddition, it was not possible to develop experiments of quench-ing by oxygen, since the metal-metal interactions, which areconsidered responsible for the luminescent behavior, are nolonger present when the product is dissolved.

Notwithstanding, we wondered whether the addition ofmetal cations as perchlorate salts or anions as tetrabutyla-monium salts to the solutions of some selected complexeshere reported, including [Tl{Au(C6Cl5)2}]n, would restorethe Au 3 3 3Tl interaction in solution and, therefore, theluminescence emission. As representative examples of thecomplexes discussed in this work, we chose compounds 5-7

and the starting complex [Tl{Au(C6Cl5)2}]n for this study.In all cases, as expected, no fluorescence emission was ob-

served after exciting at different wavelengths in the range 270-310 nm.This behaviorwas also observed upon addition of THFsolutionsof allmetal ions (Zn2þ,Cd2þ,Hg2þ, Pb2þ,Cu2þ,Al3þ,Ni2þ, Agþ, Mn2þ, Bi3þ) considered. Interestingly, an enhance-ment of the fluorescence emission intensity (CHEF effect

(chelation enhanced fluorescence)) was observed for 5-7 and[Tl{Au(C6Cl5)2}]nonlyuponadditionofaTHFsolutionofBr-,Cl-, or Ac-, but not with the other anions considered (F-, I-,H2PO4

-, ClO4-, Bz-, HSO4

-, NO3-). Correspondently, a

decrease of the band (shoulder) at around 290 was observed intheir UV-vis spectra, without formation of isosbestic points.We therefore performed spectrofluorimetric titrations of 5-7

and [Tl{Au(C6Cl5)2}]nwith Br-, Cl-, or Ac- in THF solution,by exciting, in all cases, at the maximum of the lowest energyabsorption band (shoulder) and correcting the emissiondata forthe absorbed lightwhennecessary. In all performed titrationsnoformation of precipitate was observed under the experimental

Figure 9. Excitation and emission spectra for 5 (left) and 6 (right).

Figure 10. Excitation and emission spectra for 7.

Figure 11. (a) Changes in the emission spectrum of [Tl{Au-(C6Cl5)2}]n (3.14� 10-5M,THF, 25 �C, λex=288,λem=480nm)upon addition of increasing amounts of Br-; (b) normalizedfluorescent intensity/molar ratio plots for [Tl{Au(C6Cl5)2}]n(3.14� 10-5M,THF, 25 �C) in thepresenceof increasingamountsof Br- (b), Cl- ((), and Ac- (2).


conditions (see Experimental Section). Indeed, the highestCHEF effect was observed upon addition of Br- to THF solu-tions of 5-7 or [Tl{Au(C6Cl5)2}]n, followed byCl

- in an anion/complexmolar ratioup to20:50; amuch lowerCHEFeffectwasobserved upon addition of Ac- (in some cases, especially withAc-, the plateau was not reached even after the addition of 60equiv of the anion; see Figure 11 for [Tl{Au(C6Cl5)2}]n andFigures 1S-3S for 5-7, respectively). Interestingly, the en-hancement of the fluorescence emission intensity was higherfor [Tl{Au(C6Cl5)2}]n than 5-7 upon addition of Br- and Cl-

(see Figure 12). In order to understand the species responsiblefor the observed CHEF effect in solution, we performed thefollowing experiment: 50 equiv of X- (X-=Br-, Cl-, or Ac-)was added to solutions of NBu4[Au(C6Cl5)2] in THF (2.15 �10-5 M); upon exciting at 288 nm, no fluorescence emissionwas observed for any of the solutions prepared. Subsequently,1 equiv of TlPF6was added to all the solutions, and on excitingat 288 nm, a fluorescence emission was observed with anintensity on the same order as the one recorded on adding theanions to solutions of [Tl{Au(C6Cl5)2}]n (see Figure 12) and atthe same wavelengths. On the basis of these findings, we canconclude that on adding Br-, Cl-, or Ac- to THF solutions of5-7 and [Tl{Au(C6Cl5)2}]n, possibleweak supramolecular emis-sive assemblies are formed in solution in which the Au 3 3 3Tlinteraction is, presumably, partially restored.33 [Au(C6Cl5)2]

-,Tlþ (1:1molar ratio) and theanion inhighexcessappear tobe theessential components of these assemblies, with the Au 3 3 3Tlinteraction in thembeingmuchweaker than that one in the solidstate for the starting complexes, in agreement with the muchlower λem observed in solution (see Figures 11, 1S-3S). Further-more, the strength of the Au 3 3 3Tl interaction in solution seemsto be modulated by the nature of the anion in the order Br->Cl->Ac- and to be independent of the starting complex. Infact, the λem observed upon addition of the three anions to THFsolutions of 5-7 or [Tl{Au(C6Cl5)2}]n undergoes a blue shift onpassing from Br- (480 nm) to Cl- (455 nm) and to Ac- (426nm). Whatever Au(I) 3 3 3Tl(I) 3 3 3X

- (X-=Br-, Cl-, or Ac-)assemblies are formed in solution, they must take advantage ofweak interactions between the participating components. In fact,we were neither able to isolate these species at the solid state norto ascertain their stoichiometry byMALDI-TOF spectrometry.

Conclusions

In summary, we can conclude that complexes of the type[Tl{Au(C6Cl5)2}(L)]n or [Tl2{Au(C6Cl5)2}2(L)]n (L= sterically

demanding diamine) can be easily formed from [Tl{Au-(C6Cl5)2}]n and L, in which the Au 3 3 3Tl interaction seems tobe responsible for the easy formation of luminescent imino-amine or diimine complexes upon addition of ketones, since theabsence of one of the metals precludes the formation of suchspecies. The new organic ligands, formed in the coordinationsphere ofTl(I), canbe displaced from the complexes by additionof the corresponding diamines, recovering the starting products.Interestingly, while THF solutions of the gold-thallium poly-meric complexes here reported are not emissive, by adding tothem a large excess of Br- or Cl- a partial restoration of thefluorescence emission is observed, probably because weaksupramolecular emissive assemblies are formed in solution inwhich the Au 3 3 3Tl interaction is partially restored.

Experimental Section

Instrumentation. Infrared spectra were recorded in the4000-200 cm-1 range on a Nicolet Nexus FT-IR using Nujolmulls between polyethylene sheets. C, H, N analyses werecarried out with a Perkin-Elmer 240C microanalyzer. Massspectra were recorded on aHP5989BAPI-Electrospray spectro-meter. 1HNMR spectra were recorded on a Bruker ARX 300 inTHF-D8 solutions. Chemical shifts are quoted relative to SiMe4(1H, external). Excitation and emission spectra in the solid statewere recorded with a Jobin-Yvon Horiba Fluorolog 3-22 Tau-3spectrofluorimeter. Fluorescence lifetime was recorded with aJobin-Yvon Horiba Fluorolog 3-22 Tau-3 spectrofluorimeteroperating in the phase-modulation mode. The phase shift andmodulation were recorded over the frequency range 0.2-50MHz. The lifetime data were fitted using the Jobin-Yvon soft-ware package and the Origin 6.1 program. Spectrophotometricmeasurements in solution were carried out at 25 �C using aThermo Nicolet Evolution 300 spectrophotometer. Uncor-rected emission spectra in solution were obtained with a VarianCary Eclipse fluorescent spectrophotometer. To allow compar-ison among emission intensities, we performed correctionsfor instrumental response, inner filter effect, and phototubesensitivity.34 A correction for differences in the refractive indexand for the adsorbed light was introduced when necessary.34

For spectrophotometric and spectrofluorimetric measure-ments in solution THF was used, freshly distilled upon sodium.Spectrofluorimetric titrations of the Au(I)-Tl(I) complexes5-7 and [Tl{Au(C6Cl5)2}]n with anions were performed byadding to a THF solution of the complex (3 mL) increasingvolumes of a solution of the anion as a tetrabuthylammoniumsalt. Solutions of the complexes in THF were 2.15 � 10-5 to3.14� 10-5M, and those of the anions in THFwere 2.95� 10-3

to 1.92 � 10-2 M. In all cases fluorescence emission intensitieswere corrected for the dilution effect.

General Comments. Thallium(I) hexafluorophosphate, tetra-methylenediamine, 2,20-(ethylenedioxy)bis(ethylamine), andtriethylenetetramine are commercially available and were pur-chased from Aldrich.

Synthesis of [Tl{Au(C6Cl5)2}(L)]n (L = TMDA (1), NOON

(2), trien (3)).To a solution of [Tl{Au(C6Cl5)2}]n9,10 (0.20mmol,

180.0 mg) in tetrahydrofuran (25 mL) was added tetramethyle-nediamine (TMDA) (0.20 mmol, 20.1 μL), 2,20-(ethylenedioxy)-bis(ethylamine) (NOON) (0.20 mmol, 29.2 μL), or triethylene-tetramine (trien) (0.20 mmol, 49.6 μL). After 30 min of stirring,the suspension was concentrated under vacuum and dichloro-methane (10mL)was added to precipitate orange (1), yellow (2),or white (3) solids, which were isolated after washing withdichloromethane (3 � 5 mL).

1: yield 84%. Anal. (%) Calcd for 1 (C16H12AuCl10N2Tl): C19.45, H 1.22, N 2.83. Found: C 19.33, H 1.35, N 2.48. 1HNMR(300MHz, THF-D8, ppm): δ 2.64 (br, 4H, CH2 a), 2.01 (br, 4H,

Figure 12. Normalized fluorescence emission intensity of 5-7

and [Tl{Au(C6Cl5)2}]n (A) in THF solution (25 �C) upon additionof 50 equiv of X- (Br-, Cl-, Ac-); (B) normalized fluorescenceemission intensity of THF solutions (25 �C) of NBu4[Au(C6Cl5)2]upon consecutive addition of X- (50 equiv) and TlPF6 (1 equiv).

(33) Fern�andez, E. J.; Laguna, A.; L�opez-de-Luzuriaga, J. M.;Monge, M.; Montiel, M.; Olmos, M. E. Inorg. Chem. 2007, 46, 2953. (34) Credi, A.; Prodi, L. Spectrochim. Acta 1998, 54, 159.


NH2), and 1.41 (br, 4H, CH2 b). ES(þ) m/z (%): 293[Tl(TMDA)]þ (100). ES(-) m/z (%): 695 [Au(C6Cl5)2]

- (100).FT-IR (Nujol): ν(C6Cl5) at 834 and 614 cm-1, ν(N-H st) at3356 and 3286 cm-1.

2: yield 70%. Anal. (%) Calcd for 2 (C18H16AuCl10N2O2Tl):C 20.62, H 1.54, N 2.67. Found: C 20.76, H 1.44, N 2.69. 1HNMR (300MHz, THF-D8, ppm): δ 3.59 (br, 4H, OCH2 c), 3.45(br, 4H,OCH2 b), 2.86 (br, 4H,OCH2 a), and 2.24 (br, 4H,NH2).ES(-) m/z (%): 695 [Au(C6Cl5)2]

- (100). FT-IR (Nujol):ν(C6Cl5) at 835 and 610 cm-1, ν(N-H st) at 3371, 3338, 3315,and 3274 cm-1.

3: yield 83%. Anal. (%) Calcd for 3 (C18H18AuCl10N4Tl): C20.66, H 1.73, N 5.36. Found: C 20.56, H 1.64, N 5.18. 1HNMR(300 MHz, THF-D8, ppm): δ 2.75 (m, 4H, CH2 a), 2.70 (s, 4H,NHCH2 c), and 2.59 (m, 4H, NHCH2 b). ES(-) m/z (%):695 [Au(C6Cl5)2]

- (100). FT-IR (Nujol): ν(C6Cl5) at 831 and610 cm-1, ν(N-H st) at 3378, 3345, and 3308 cm-1.Synthesis of [Tl2{Au(C6Cl5)2}2(trien)]n (4). To a solution of

[Tl{Au(C6Cl5)2}]n9,10 (0.20 mmol, 180.0 mg) in toluene (25 mL)

was added triethylenetetramine (trien) (0.10 mmol, 24.8 μL).After 30 min of stirring, n-hexane (10 mL) was added. Product 4was isolated as an orange solid after being filtrated and washedwith toluene-n-hexane (1:1) (3� 5 mL). Yield: 97%. Anal. (%)Calcd for 4 (C30H18Au2Cl20N4Tl2): C 18.51, H 0.93, N 2.88.Found: C 18.72, H 0.91, N 2.93. 1H NMR (300MHz, THF-D8,ppm):δ 2.82 (m, 4H,CH2 a), 2.77 (s, 4H,NHCH2 c), and 2.70 (m,4H,NHCH2 b). ES(-)m/z (%): 695 [Au(C6Cl5)2]

- (100). FT-IR(Nujol): ν(C6Cl5) at 839 and 607 cm-1, ν(N-H st) at 3383 and3312 cm-1.Synthesis of [Tl{Au(C6Cl5)2}(L

x)]n (Lx = {OdC(CH3)CHC-

(CH3)NH(CH2)4NH2} (5), {OdC(CH3)CHC(CH3)NHCH2-CH2}2 (6)). To a solution of [Tl{Au(C6Cl5)2}(TMDA)]n (1)(0.20 mmol, 197.6 mg) in tetrahydrofuran (25 mL) was addedacetylacetone (0.20 mmol, 21 μL (5); 0.45 mmol, 46 μL (6)).After 10 min of stirring, the suspension was concentrated undervacuum and dichloromethane (10 mL) was added to precipitateyellow solids.

5: yield 79%.Anal. (%)Calcd for 5 (C21H18AuCl10N2OTl): C23.57, H 1.70, N 2.62. Found: C 23.72, H 1.66, N 2.68. FT-IR(Nujol): ν(O 3 3 3H-N st) at 3600 cm-1, ν(NH2 st) at 3271 cm

-1,ν(CdO) at 1605 cm-1, ν(CdN st) at 1560-1505 cm-1, andν(C6Cl5) at 838 and 610 cm-1.

6: yield 85%. Anal. (%) Calcd for 6 (C26H24AuCl10N2O2Tl):C 27.10, H 2.10, N 2.43. Found: C 27.35, H 2.05, N 2.37.1H NMR (300 MHz, THF-D8, ppm): δ 10.88 (s, 2H, Hz),4.89 (s, 2H, CHx), 3.28 (br, 4H, CH2 c), 1.90 (s, 6H, CH3 a),1.85 (s, 6H, CH3 b), and 1.29 (m, 4H, CH2 d). ES(þ) m/z (%):205 [Tl]þ (100). ES(-) m/z (%): 695 [Au(C6Cl5)2]

- (100).FT-IR (Nujol): ν(O 3 3 3H-N st) at ∼3600 cm-1, ν(CdO)at 1605 cm-1, ν(CdN st) at 1550-1500 cm-1, and ν(C6Cl5)at 835 and 610 cm-1.

Synthesis of [Tl{Au(C6Cl5)2}{OdC(CH3)CHC(CH3)NHCH2-

CH2OCH2}2]n (7).To a solution of [Tl{Au(C6Cl5)2}(NOON)]n (2)(0.20 mmol, 209.6 mg) in tetrahydrofuran (25 mL) was addedacetylacetone (0.45mmol, 46 μL).After 30min of stirring, the solu-tionwas concentratedundervacuumanddichloromethane (10mL)was added to precipitate a yellow solid, which was isolated afterbeing filtrated and washed with dichloromethane-n-hexane (1:1)(3 � 5 mL). Yield: 89%. Anal. (%) Calcd for 7 (C28H28AuCl10-N2O4Tl): C 27.74, H 2.33, N 2.31. Found: C 27.46, H 2.28, N 2.37.1HNMR (300MHz, THF-D8, ppm): δ 10.83 (br, 2H, Hz), 4.91 (s,2H, Hx), 3.63 (br, 4H, CH2 e), 3.61 (t, 4H, CH2 d), 3.40 (m, 4H,CH2 c), 1.95 (s, 6H,CH3 a), and1.90 (s, 6H,CH3 b).ES(-)m/z (%):695 [Au(C6Cl5)2]

- (100). FT-IR (Nujol): ν(O 3 3 3H-N st) at 3605cm-1, ν(CdO) at 1600 cm-1, ν(CdN st) at 1533 cm-1, andν(C6Cl5) at 833 and 612 cm-1.

Crystallography. Crystals were mounted in inert oil on glassfibers and transferred to the cold gas stream of a Nonius KappaCCD diffractometer equipped with an Oxford Instruments low-temperature attachment. Data were collected using monochro-mated Mo KR radiation (λ = 0.71073 A). Scan type: ω and φ.Absorption corrections: semiempirical (based on multiplescans). The structures for complexes 1, 4, and 7 were solved bydirect methods and for complex 6 using Patterson methods,and refined on F2 using the program SHELXL-97.35 All non-hydrogen atoms were refined anisotropically. Hydrogen atomswere included using a riding model. Complex 4 crystallizeswith a molecule of toluene per Au2Tl2 unit. Further details ofthe data collection and refinement are given in Table 1. Selectedbond lengths and angles are collected in Tables 2-5 andcrystal structures of complexes 1, 4 3 toluene, 6, and 7 inFigures 1-6.

Acknowledgment. This work was supported by TheDGI(MEC)/FEDER (CTQ2007-67273-C02-02). M.M.and T.L. thank CAR and MICINN for a grant, respec-tively. A.G. and V.L. thank the Universit�a degli Studi diCagliari for financial support.

Supporting Information Available: UV-vis data of 1-7 and[Tl{Au(C6Cl5)2}]n in THF solution at 25 �C (Table 1S); changesin the emission spectrum of 5-7 upon addition of increasingamounts of Br-, and normalized fluorescent intensity/molarratio plots for 5-7 in the presence of increasing amounts of Br,Cl-, and Ac-. X-ray crystallographic files in CIF format for thestructural characterization of complexes 1, 4 3 toluene, 6, and 7.This material is available free of charge via the Internet at http://pubs.acs.org.

(35) Sheldrick, G. M. SHEXL-97; University of G€ottingen: G€ottingen,Germany, 1997.

Long-Chain Ketimine Synthesis in a Gold−Thallium Polymer

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