Organometallic Fragments Coordinated to a Multiisocyanide Ligand and Their Physical Properties

Preparation of a triisocyanide ligand, 1,3,5-tris[(4-isocyano-3,5-diisoproyl-phenyl)ethynyl]benzene (5), is presented.
Ligand 5 is obtained in three steps in 76% overall yield. Reaction of 5 with (η5-Cp*)Rh(Cabs,s')(Cabs,s'= 1,2-S2C2B10H10-S,S‘) produced the rhodadithiolene adduct [{(η5-Cp*)Rh(Cabs,s')(CNC6H2iPr2-2,6-C⋮C-3)}3C6H3-1,3,5]
(6). Ligand 5 reacts with Cr(CO)5(THF) to give the triisocyanide complex [{Cr(CO)5(CNC6H2iPr2-2,6-C⋮C-3)}3C6H3-1,3,5] (8) and with [AuCl(SMe2)] to give the triisocyanide complex [{AuCl(CNC6H2iPr2-2,6-C⋮C-3)}3C6H3-1,3,5]
(9). As revealed by a single-crystal X-ray diffraction study, the C(9)−N(3)−C(61) angle of 5.9° of trichromium
complex 8 occurs in the plane of the bridge and the gold center has a slightly bent linear configuration with a
Cl(1)−Au(1)−C(21) angle of 175.4(4)°. The rhenation and platination of 5 employing [Re(bpy)(CO)3(AN)]PF6 (AN=
acetonitrile) and [(C∧N∧N)PtCl] ((HC∧N∧N)= 6-phenyl-2,2‘-bipyridine) yielded the luminescent Re(I) and Pt(II)
complexes. Full characterization includes structural study of complexes 2, 8, and 9.