Rhodium and Iridium Phosphinothiolato Complexes. Synthesis and Crystal Structures of Mononuclear [M(cod)(S,P-SC2B10H10PPh2)] and Dinuclear [M2
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- 作者：Heung-Sae Lee ; Jin-Young Bae ; Dae-Hyun Kim ; Hoon Sik Kim ; Sung-Joon Kim ; Sungil Cho ; Jaejung Ko ; and Sang Ook Kang
- 刊名：Organometallics
- 出版年：2002
- 出版时间：January 7, 2002
- 年：2002
- 卷：21
- 期：1
- 页码：210 - 219
- 全文大小：181K
- 年卷期：v.21,no.1(January 7, 2002)
- ISSN：1520-6041
文摘
The synthesis of new group 9 metal complexes containing the P,S-chelate ligands P,S-[SC2B10H10(CH2)nPPh2] (n = 0, CabP,S (2a); n = 1, CabCH2P,S (2b)) is described. Two newphosphinothiolato complexes of the type [M(CabP,S)(cod)] (M = Rh (3a), Ir (3b); cod = 1,5-cyclooctadiene) have been synthesized by the reaction of chloride-bridged dimers [M(
-Cl)(cod)]2 with 2 mol equiv of the corresponding lithium phosphinothiolato ligand LiCabP,S (2a).The X-ray crystal structure determination of 3 shows a mononuclear, square-planar cis-P,Smetal complex with a cod ligand. Carbonylation of the cod complexes 3 yields the dinuclearcomplexes [M(-S-CabP,S)(CO)]2 (where M = Rh (4a), Ir (4b)). The molecular structures revealthat the two metal atoms are bridged by the two thiolato ligands, and the carbonyls completethe coordination of the metal atoms. Dinuclear complexes 4 were also formed upon reactionof carbonyl dimers [M(-Cl)(CO)2]2 with 2 equiv of 2a. Addition reactions of the dinuclearcomplexes 4 with triethylphosphine give the monosubstituted mononuclear metal complexes[M(CabP,S)(CO)(PEt3)] (where M = Rh (5a), Ir (5b)), which are obtained as trans isomers.The molecular structure of complex 5a has been determined by X-ray diffraction methods.In an analogous manner, reaction of 2b with [Rh(CO)2(acac)] (acac = acetylacetone) producesa dinuclear thiolato-bridged complex, [Rh(-S-CabCH2P,S)(CO)]2 (6). Complex 6 was characterized by single-crystal X-ray analysis. Reacting 6 with 2 equiv of PEt3 gave the trans-phosphinoP,S-chelate complex [Rh(CabCH2P,S)(CO)(PEt3)] (7), analogous to 5. The mono- and dinuclearP,S-chelates 4 and 5 catalyze the carbonylation of methanol to acetic acid. In particular,the dinuclear rhodium carbonyl complex 4a is much more effective in catalyzing thecarbonylation of methanol to acetic acid than the previously known catalyst [RhI2(CO)2]-.
-Cl)(cod)]2 with 2 mol equiv of the corresponding lithium phosphinothiolato ligand LiCabP,S (2a).The X-ray crystal structure determination of 3 shows a mononuclear, square-planar cis-P,Smetal complex with a cod ligand. Carbonylation of the cod complexes 3 yields the dinuclearcomplexes [M(-S-CabP,S)(CO)]2 (where M = Rh (4a), Ir (4b)). The molecular structures revealthat the two metal atoms are bridged by the two thiolato ligands, and the carbonyls completethe coordination of the metal atoms. Dinuclear complexes 4 were also formed upon reactionof carbonyl dimers [M(-Cl)(CO)2]2 with 2 equiv of 2a. Addition reactions of the dinuclearcomplexes 4 with triethylphosphine give the monosubstituted mononuclear metal complexes[M(CabP,S)(CO)(PEt3)] (where M = Rh (5a), Ir (5b)), which are obtained as trans isomers.The molecular structure of complex 5a has been determined by X-ray diffraction methods.In an analogous manner, reaction of 2b with [Rh(CO)2(acac)] (acac = acetylacetone) producesa dinuclear thiolato-bridged complex, [Rh(-S-CabCH2P,S)(CO)]2 (6). Complex 6 was characterized by single-crystal X-ray analysis. Reacting 6 with 2 equiv of PEt3 gave the trans-phosphinoP,S-chelate complex [Rh(CabCH2P,S)(CO)(PEt3)] (7), analogous to 5. The mono- and dinuclearP,S-chelates 4 and 5 catalyze the carbonylation of methanol to acetic acid. In particular,the dinuclear rhodium carbonyl complex 4a is much more effective in catalyzing thecarbonylation of methanol to acetic acid than the previously known catalyst [RhI2(CO)2]-.