Synthesis and characterisation of azido- and thiocyanato-gallium(III) porphyries. Crystal structure of azido(2,3,7,8,12,13,17,18-octaethyl-porphyrinato)gallium(III)
Abstract
Gallium(III) porphyrin complexes of the type Ga(por)X [por = 2,3,7,8,12,13,17,18-octamethyl-,2,3,7,8,12,13,17,18-octaethyl-, 5,10,15,20-tetraphenyl-, 5,10,15,20-tetra-m-tolyl-, or 5,10,15,20-tetra-p-tolyl-porphyrinate(2–); X = N3 or SCN] have been prepared. The stereochemistry of the metal has been established by i.r. and 1H n.m.r. measurements and confirmed by the crystal structure determination of the title compound by X-ray diffraction methods using Cu-Kα radiation. Crystals are monoclinic, space group P21/c, with a= 13.469(1), b= 13.497(1), c= 19.050(2)Å, β= 106.28(1)°, and Z= 4; R(F)= 0.041, R′(F)= 0.044 for 6 295 reflections. The gallium atom is five-co-ordinated by the four nitrogen atoms (Np) of the porphyrin plane and one nitrogen atom N(5) of the azido group: mean Ga–Np 2.034(3), Ga–N (5)1.955(2)Å, N (5)–Ga–Np 100.3(10), Ga–N (5)–N (6) 120.8(1)°.