Synthesis of carbaborane rhodium–platinum complexes: crystal structure of [RhPt(µ-H)(µ-CO)(PEt₃)₂(PPh₃)(η⁵-7,9-C₂B₉H₁₁)]

Abstract

Treatment of [PtCI(H) (PEt,),] with [NEt,] [Rh(CO) (PPh,) (q5-7,9-C,B,Hll)] in thf (tetrahydrofuran) in the presence of TIBF, affords [RhPt(p-H) (p-CO) (PEt,),( PPh,) (q5-7,9-C,B,H,,)], the structure of which has been established by X-ray diffraction. On heating at reflux in thf for several days the compound yields [ RhPt(p-ts:q 5-7,9-C,B,Hl,) (CO) (PEt,),( PPh,)], a product in which the rhodium-platinum bond is spanned by an exopolyhedral cage B-Pt linkage. Reactions between the platinum compounds [PtCI(R)L,] (R = M e or Ph; L = PEt,, PPh, or PMe,Ph) and [NEt,][Rh(CO)(PPh3)(q5-7,n-C,BgH,,)] (n = 8 or 9) afford several dimetal complexes in which the Rh-Pt bonds are bridged by exopolyhedral cage B-H -Pt or B-Pt bridge bonds. The latter are formed from the former by loss of RH molecules, and this process is favoured for Rh(q5-7,9-C,BgHll) versus Rh(q5-7,8-C,B,Hll), and in the order L = PPh, < PMe,Ph < PEt, for the ligands on platinum. The NMR data (lH, 13C-{lH}, llB-{lH} and "P-('H}) are reported and discussed in relation t o the structures of the products.

Side-on coordination of boryl and borylene complexes to cationic coinage metal fragments

“…It has been observed that ligands in Au(I) complexes that deviate from linear geometry cause the energies of the 5d orbitals to rise, which strengthens the backdonation from the Au(I) center to the ligand (CO). 44 It is interesting to note that the structural differences observed between borylene coordination to coinage metals and other transition metal fragments closely reect those reported for analogous alkylidyne chemistry: when coordinated to Au + , alkylidynes also exhibit larger Mm C-R angles and shorter Mm C bonds than bridging alkylidynes with most other metals, where the m CR vector is closer to perpendicular to the M-Au bond 4,[45][46][47][48][49][50] These ndings further demonstrate the unique bonding characteristics of coinage metals.…”

Amides of gold(I) diphosphines prepared from N-heterocyclic sources and their in vitro and in vivo screening for anticancer activity

“…Gold(I) starting materials (μ-1,2-bis(diphenylphosphino)ethane)bis(chlorogold) [49], (μ-1,3-bis(diphenylphosphino)propane)bis(chlorogold) [50], (μ-1,5-bis(diphenylphosphino)pentane)bis(chlorogold) [51], (μ-1,6-bis(diphenylphosphino)hexane)bis(chlorogold) [52] and chloro(trimethylphosphine)gold [53] were prepared by substitution of tetrahydrothiophene (tht) in [(tht)AuCl] [54,55] with the appropriate phosphine. The synthesis of (μ-1,2-bis(dimethylphosphino)ethane)bis (chlorogold) followed the same method.…”

Transition Metal Metallacarbaboranes

“…Figure 20 depicts several examples of such products. 279 Metallacarbaboranes featuring metal-metal bonds have received much attention. Reactions of [Rh(CO)L(R 2 C 2 B 9 H 9 )]~ anions (L = CO or PPh 3 , R = H or Me) with chlorogold reagents afford products having direct Au-Rh bonds; alternatively, salts of [10-en^6>-[Au-PPh 3 ]-n/V/o-Me 2 C 2 B 9 H 9 ]" can be treated with rhodium complexes to give products in which the carbaborane ligand is transferred from gold to rhodium.…”