NONLINEAR-OPTICAL MATERIALS CONTAINING MOLYBDENUM OR TUNGSTEN MONONITROSYL REDOX CENTERS - DIAROMATIC AZO DERIVATIVES

The following compounds have been prepared: [M(NO)L(X)(n)(EC(6)H(3)(R-3)[N=NC6H3(R'-3)(R''-4)-4]}(2-n)] [L = tris(3,5-dimethylpyrazolyl)hydroborate; R'' = (eta(5)-C5H4)Fe(eta(5)-C5H5), E = O, R = R' = H, M = Mo, X = Cl or I, n = 0 or 1; E = NH, R = R' = H, n = 1, M = Mo or W, X = Cl; E = NH, R = Me, R' = H, n = 1, M = Mo, X = F, Cl, Br, I or OC6H11; M = W, X = Cl; E = NH, R = R' = Me, n = 1, M = Mo. X = Cl or I; M = W, X = Cl; R'' = NMe(2). E = O, R = R' = H, M = Mo, X = Cl or I, n = 0 or 1; M = W, X = Cl, n = 1; E = NH, R = R' = H, n = 1, M = Mo, X = Cl or I; M = W, X = Cl], [M(NO)L(X){OC10H6[N=NC6H4(Oet-4-4]}] (M = Mo, X = Cl or I; M = W, X = Cl) and [Mo(NO)L(Cl)(NHC6H3(Me-3){N=NC6H3 (Me-3)[N=NC6H3(Me-3)(R''-4)-4]}-4)]. Several of the ferrocenyl derivatives have been found to produce frequency doubling of radiation at 1907 nm. whereas the derivatives containing NMe(2) or OEt groups do not. A single-crystal X-ray diffraction study has shown that [W(NO)LCl{NHC6H3(Me-3)[N=NC6H4(R''-4}].CH2Cl2 crystallises in the space group P2(1) and is isostructural with its molybdenum counterpart; in these crystals the molecules appear to be favourably oriented to produce phase matching.