Collect. Czech. Chem. Commun. 1999, 64, 883-894

N,S-Chelating Amino-ortho-carboranethiolate Complexes of Rhodium and Iridium: Synthesis and Reactivity. X-Ray Crystal Structures of (η4-C8H12)Rh[(NMe2CH2)SC2B10H10] and (CO)2Rh[(NMe2CH2)SC2B10H10]

Seung-Won Chunga, Jaejung Koa,*, Kwonil Parkb, Sungil Chob and Sang Ook Kanga,*

a Department of Chemistry, Korea University, 208 Seochang, Chochiwon, Chung-nam 339-700, Korea
b Department of Chemical Engineering, Junnong-dong 90, Seoul City University, Seoul 130-743, Korea


The reaction of [M(μ-Cl)(cod)]2 (M = Rh, Ir; cod = cycloocta-1,5-diene) with two equivalents of the lithium ortho-carboranethiolate derivative LiCabN,S 2 [LiCabN,S = closo-2-(dimethylaminomethyl)-1-(lithiumthiolato)-ortho-carborane] produced the four-coordinated metallacyclic compounds, CabN,SM(cod) 3 (M = Rh 3a, Ir 3b), in which the metal atom was stabilized via intramolecular N,S-coordination. These new compounds have been isolated in high yields and characterized by IR and NMR spectroscopy. The structure consists of an amino-ortho-carboranethiolate fragment bonded to (cod)Rh(I) via nitrogen and sulfur, so as to give the metal a square-planar environment. Subsequent carbonylation reactions of 3a, 3b result in the quantitative formation of the corresponding (amino-ortho-carboranethiolato)(carbonyl)metal N,S-chelates CabN,SM(CO)2 4 (M = Rh 4a, Ir 4b). The metal carbonyl complexes 4a, 4b have been isolated and characterized by spectroscopic and compound 4a also by X-ray diffraction techniques. The molecular structure of 4a reveals that the rhodium atom is coordinated by nitrogen and sulfur atoms of the amino-ortho-carboranethiolate ligand, and two carbonyl ligands complete the coordination of the metal atom.

Keywords: Boranes; Carboranes; N,S-Ligands; Chelates; Intramolecular N,S-coordination; Amino-ortho-carboranethiolate; Group 9 transition metals; Carbonylation.