Bulky amidinate complexes of indium(III). Synthesis and structure of [CyNC((t)Bu)NCy]2InCl

Reaction of 2 equiv of lithium dicyclohexylacetamidinate with InCl3 affords the new species In[CyNC(Me)NCy]Cl-2 (Cy = cyclohexyl) (1). Compound 1 reacts with MeLi to yield In[CyNC(Me)NCy]2CH3 (2) and also reacts with a third equivalent of amidinate to yield In[CyNC(Me)NCy](3) (3). Two new bulky amidinate-ligands are prepared by the addition of 'BuLi to CyN=C=NCy and Me(3)SiN=C=CSiMe(3), respectively. Subsequent reactions with InCl3 lead to the high-yield syntheses of In[CyNC(CMe(3))NCy]Cl-2 (4) and [Me(3)SiN(CMe(3))NSiMe(3)]2InCl. (5). Spectroscopic and elemental analyses confirm the formulas of all of these new species. Compound 4 is further characterized by X-ray crystallography and shown to possess a distorted trigonal bipyramidal coordination geometry around the metal center with the chloride group in the equatorial position. Crystal data for 4: triclinic, <P(1)over bar>, a = 12.545(7) Angstrom, b = 13.482(8) Angstrom, c = 11.965(6) Angstrom, alpha = 102.08(5)degrees, beta = 92.00(5)degrees, gamma = 64.36(4)degrees, Z = 2, R = 0.029, R(w) = 0.045.