Nitrogen tripod ligand/oxygen tripod ligand indium(III) complexes: The first structurally characterized Trofimenko-Klaui complex [eta(5)-(C5H5)Co{P(OCH3)(2)(O)}(3)InHB(pz)(3)][InCl4] (pz = pyrazol-1-yl)

Indium(III) complexes [L(R)InTp*]X (L-R = (cyclopentadienyl)-tris[diorganyl phosphi(ni)to-P]cobaltate(1-) [eta (5)-(C5H5)Co-{PR2(O)}(3)](-), R = OCH3, CH2CH3; Tp* = hydrotris(3,5-dimethylpyrazol- l-yl)borate) have been prepare d from [Tp*InCl2(NCCH3)] and AgLOMe or T1L(Et). Alternatively, equilibratio n of a 1:1 mixture of the homoleptic complexes [In(L-OMe)(2)][PF6] and [In( Tp)(2)][PF6] in aqueous methanol slowly yielded the heteroleptic indium(III ) complex [L(OMe)InTp][PF6]. An X-ray crystal structure determination revea led a fac-N3O3 coordination sphere for the [L-OMe- InTp][InCl4] complex. Th ese indium compounds represent the first structurally characterized complex es where the tripodal oxygen ligand L-R and the tripodal nitrogen ligand Tp are coordinated to the same metal center. Indium(III) is classified as a c lass a, i.e, a hard metal ion, but it evidently prefers an antisymbiotic ar rangement of ligands.