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The organodiselone ligands 1,1‐bis(3‐methyl‐4‐imidazolin‐2‐selone)methane (L1) and 1,2‐bis(3‐methyl‐4‐imidazolin‐2‐selone)ethane (L2) have been used for the synthesis of homopolynuclear TlI[{Tl(L)}PF6]n·(mMeCN)n[L= L1, m= 1 (1); L = L2, m= 0 (2)] and discrete heteropolynuclear [Tl{Au(C6Cl5)2}(L)] [L = L1(3), L2(4)] complexes. The crystal structures of complexes 1and 3have been determined through X‐ray diffraction studies. Complex 1consists of alternating thallium(I) centres and bidentate Se‐donor ligands that result in polymeric chains. The crystal structure of 3is formed by [Tl(L1)]+cations and [Au(C6Cl5)2]–anions joined together by an unsupported Au···Tl interaction. Compounds 3and 4are luminescent in the solid state at room temperature and at 77 K with lifetimes in the nanosecond range. DFT and time‐dependent (TD)‐DFT calculations have been carried out on different model systems including the free ligand L1, a representative model of complex 1and a model system of complex 3. The character of the frontier molecular orbitals and the TD‐DFT prediction of the absorption spectra are used to explain the origin of the luminescence of complexes 3and 4as an admixture of metal–metal (Au–Tl)‐to‐ligand charge transfer (MMLCT) and intraligand (IL) transitions as observed experimentally.

Treatment of pyrazole ligands HL HL = pyrazole or 3,5dimethylpyrazole with the goldI compound [AuC6F5tht] tht = tetrahydrothiophene gives either the complexes [AuC6F5HL] or, if the reaction is carried out in a molar ratio of 1:2 and in the presence of a base, the pyrazolate compound [NBu4][{AuC6F5}2μL]. Binuclear derivatives with bridging pyrazolate ligands have been obtained by treatment of the ligands with [OAuPPh33][ClO4] or [Au2Cl2μdppf] dppf = 1,1′bisdiphenylphosphanylferrocene and Na2CO3, to give [AuPPh32μL][ClO4] or [Au2μLμdppf]Cl. Treatment of [AgOTfPPh3] with the pyrazole ligands affords the dimeric species [Ag2μOTf2HL2PPh32]. GoldIII derivatives have been accessed by treatment of the pyrazole ligands with [AuC6F53OEt2] or [AuC6F52OEt22][ClO4], affording the species [AuC6F53HL] or [AuC6F52HL2][ClO4]. GoldIII pyrazolate derivatives of the form trans[NBu4][AuC6F52ClL] or [{AuC6F52}2μL2] have been prepared from [NBu4][AuC6F52Cl2] or [AuacacC6F52]. Xray structural characterization has been carried out for eight compounds. © WileyVCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008

The reaction of Li(2-CH2-6-RC5H3N) with [AuCl(PPh3)] leads to the mononuclear complexes [Au(2-CH2-6-RC5H3N)(PPh3)] (R 4;= 4;H, Me). These react further with other copper, silver or gold compounds to give heteronuclear derivatives, [M{Au(2-CH2-6-RC5H3N)(PPh3)}2][X] (M 4;= 4;Cu, X 4;= 4;PF6 or M 4;= 4;Ag, X 4;= 4;ClO4), or the dinuclear complex [Au(2-CH2-6-MeC5H3N)]2. The crystal structure of [Ag{Au(2-CH2-6-MeC5H3N)(PPh3)}2][ClO4] has been determined by X-ray diffraction studies and shows short interactions between the gold and silver centres.

The synthesis and properties of gold complexes with 1,1-bis(diphenylphosphino)ferrocene (dppf ), its sulfide (dppfS2) and disubstituted dithiocarbamate or thiolate ferrocene derivatives as ligands are reviewed. The ability of these metalloligands to modify their steric bite in order to adapt to different geometric requirements of the metal centres has allowed the synthesis of several gold complexes with unusual geometries and novel structures. The potential of the new compounds for a number of applications is considered.

Treatment of vinylidenebis(diphenylphosphine) with elemental sulfur under reflux led to vinylidenebis(diphenylphosphine) disulfide, (SPPh2)2C&z.dbd6;CH2, in good yields. Its co-ordination to a gold(III) centre activates the carbon–carbon double bond. Thus, the chelate complex [Au(C6F5)2{(SPPh2)2C&z.dbd6;CH2}]ClO4 reacted rapidly with carbon- or oxygen-donor nucleophiles (Nu–), such as acac– (acetylacetonate), CN–, C5H5– or OEt–, forming methanide-type derivatives [Au(C6F5)2{(SPPh2)2CCH2Nu}]. These products can be considered as intermediates in Michael-type additions of HNu to the C&z.dbd6;C bond, which in this particular case display high stabilities, allowing their isolation as solids. The crystal structure of the cyclopentadienyl derivative has been established by X-ray crystallography and displays a square-planar gold(III) centre with a cis disposition of the pentafluorophenyl groups and sulfur atoms of the chelating ligand, and sp2 hybridization of the endocyclic carbon atom with partial P–C double-bond character.

The reaction of 1-methyl-2-sulfanyl-1,2-dicarba-closo-dodecaborane with the gold(I) complexes [AuCl(L)] afforded the neutral thiolate derivatives [Au(SCB10H10CMe)L] (L = PPh3 1, PPh2Me 2 or AsPh3 3). Further reaction of 1 with [Au(O3SCF3)(PPh3)] gave the dinuclear species [Au2(SCB10H10CMe)(PPh3) 2][O3SCF3] 4. Another dinuclear complex, [Au2(SCB10H10CMe)2(- dppe)] 5, can be synthesized by reaction of [Au2Cl2(-dppe)] (dppe = Ph2PCH2CH2PPh 2) with 2 equivalents of HSCB10H10CMe. The anionic derivatives [N(PPh3)2][Au(SCB10H10CMe) Cl] 6 and [N(PPh3)2][Au(SCB10H10CMe) 2] 7 were obtained by reaction of HSCB10H10CMe with [N(PPh3)2][AuCl2] in a 1∶1 or 2∶1 molar ratio, respectively. Finally, by reaction of the thiol with suitable gold(III) precursors the anionic [NBu4][Au(C6F5)3(SCB 10H10CMe)] 8 or the neutral [Au{(PPh2)2C2B9H 10}(SCB10H10CMe)2] 9 derivatives were synthesized. Complexes 1, 3 and 6 have been characterised by X-ray diffraction studies.

The ligand 1,1′-bis(diphenylthiophosphoryl)ferrocene, dptpf, reacted with various silver complexes to afford two-, three- or four-co-ordinate species. Thus the reaction of dptpf with [Ag(OClO3)(PPh3)] in 1∶1 or 1∶2 molar ratio gave the three-co-ordinate [Ag(dptpf )(PPh3)]ClO4 or the linear [Ag2(dptpf )(PPh3)2][ClO4]2 derivatives. Similarly, the treatment of dptpf with AgClO4 in 2∶1 or 1∶1 molar ratio afforded the homoleptic compounds [Ag(dptpf )2]ClO4 or [Ag(dptpf )]ClO4; in the latter dptpf acts as a trans-chelating ligand. The complex [Ag(dptpf )]ClO4 can react further with bidentate ligands such as 2,2′-bipyridine (bipy) or bis(diphenylthiophosphoryl)methane, (SPPh2)2CH2, leading to the four-co-ordinate [Ag(dptpf )(bipy)]ClO4 or the four-co-ordinate polymeric species [Ag2(µ-dptpf ){(SPPh2)2CH2}2]n [ClO4]2n , which was characterised by X-ray diffraction.

The reaction of 1,2-disulfanyl-1,2-dicarba-closo-dodecaborane, under basic conditions, with [N(PPh3)2][AuCl4] or [AuCl3(tht)]–NBu4Br (molar ratio 2∶1) (tht = tetrahydrothiophene) resulted in the formation of the homoleptic gold(III) derivative Q[Au(S2C2B10H10)2 ] [Q = N(PPh3)2 or NBu4]. Treatment of this complex with hydrazine or phenylhydrazine partially degraded one or both carborane cages, respectively. The complexes [NBu4][Au(S2C2B10H10 )2] and [NBu4]2[Au(S2C2B9 H10)(S2C2B10H10 )] have been characterized by X-ray diffraction studies.

Treatment of the tetrathiometalates [NH4]2[MS4] (M = Mo or W) with [AuCl(AsPh3)] (molar ratio 1∶2) gave the trinuclear species [MS4(AuAsPh3)2] (M = Mo 1 or W 2). Stepwise substitution of the arsine ligand afforded the complexes [MS4(AuAsPh3)(AuPPh3)] (M = Mo 3 or W 4) or [MS4(AuPPh3)(AuPPh2Me)] (M = Mo 5 or W 6). The reaction with gold(I) complexes [AuCl(ylide)] follows a different pathway depending on the ylide ligand; with the less sterically demanding CH2PPh2Me the species [MS4(AuCH2PPh2Me)2] (M = Mo 7 or W 8) with three-co-ordinate gold were formed, but the ylide CH2PPh3 led to [MS4(AuCH2PPh3)2] (M = Mo 9 or W 10) with one three- and one two-co-ordinate gold centre. The crystal structures of complexes 1 and 10 were determined by X-ray diffraction.

The first gold complex, [Se(AuPPh3)4](CF3SO3)2, with a µ4-selenido ligand has been prepared; the crystal structure reveals a square pyramidal geometry with short gold–gold interactions.

(Trimethylsilylmethyl)gold(I) complexes [{Au(CH2SiMe3)}2(µ-P–P)] (P–P 4;= 4;dppm or dppe) reacted with silver derivatives (AgOClO3 or AgOSO2CF3) affording trinuclear [Au2Ag(CH2SiMe3)2(µ-P–P)A] (A 4;= 4;OClO3 or OSO2CF3) or pentanuclear [Au4Ag(CH2SiMe3)4(µ-dppm)2]SO3CF3 complexes; the cation of the latter consists of a novel Au4Ag core with four AgI–AuI non-supported bonds.

The polymeric complex [Ag{Fc(S2CNEt2)2}]n[ClO4]n, in which the silver centres are bonded to two sulfur atoms of different ferrocene moieties and also to the cyclopentadienyl rings in an η2 fashion, is reported.