Inorganic Chemistry, Vol.36, No.13, 2879-2883, 1997
Linear-Chain Formation by an Oxovanadium(V) Complex of P-Methylhexahomotrioxacalix(3)Arene
The oxovanadium(V) complex 4 can be readily synthesized by the reaction of the lithium salt of p-methylhexahomotrioxacalix[3]arene trianion 3 with VOCl3. Infrared spectra indicate a terminal V=O for complex 4 in solution and V=O ... V dative interactions in the solid state consistent with the formation of a mu-oxo-bridged linear chain polymer 1 (M = V, Y = O, X-3 = trianion of macrocycle 2a). Vanadium-51 NMR spectra indicate increased shielding for the linear chain polymer in the solid state compared to complex 4 in solution. Complex 4 and its linear chain polymer are proposed to have the oxovanadium group contained within the cup of the macrocycle ligand as shown in structures 5 and 7, respectively, where the cone represents macrocycle 2a.
Keywords:MOLYBDENUM-NITRIDE-TRICHLORIDE;CRYSTAL-STRUCTURE;TRIPLE BONDS;V-51 NMR;MOLECULAR-STRUCTURES;IR-SPECTRUM;SOLID-STATE;POLYMERS;METALLOMACROCYCLES;PHTHALOCYANINES