Structural interactions of planar and non-planar bis(1,2-dithiosquarato)metalate host lattices with Cu-II complexes - Structure and EPR investigations

1,2-Dithiosquaratometalates (M = Cu, Ni, Zn) are available by direct synthe sis from metal salts with dipotassium-1,2-dithiosquarate. The structural in fluence of the planar and nonplanar host lattice systems (BzlEt(3)N)(2)[Cu/ Ni(dtsq)(2)] and (BzlEt(3)N)(2)[Cu/Zn(dtsq)(2)] on the geometrical and elec tronic structure of the Cu-II guest complex [Cu(dtsq)(2)](2-) is studied by EPR spectroscopy. The used host lattices (BzlEt(3)N)(2)[Ni(dtsq)(2)] (plan ar) and (BzlEt(3)N)(2)-[Zn(dtsq)(2)] (tetrahedral) are characterized by X-r ay structure analysis. (BzlEt(3)N)(2)[Ni(dtsq)(2)] crystallizes in the tric linic unit cell P (1) over bar with a=9.1021(8)Angstrom, b=9.4190(8)Angstro m, c = 11.0119(10)Angstrom, alpha = 92.8560(10)degrees, beta = 95.375(2)deg rees, gamma = 104.5180(10)degrees and Z = 1. (BzlEt(3)N)(2)[Zn(dtsq)(2)] cr ystallizes in the monoclinic unit cell C2/c with a=21.1299(14) Angstrom, b = 16.6641(11)Angstrom, c=13.8324(9) Angstrom, beta = 123.9100(10)degrees an d Z = 4. The g and A(Cu) tensors in the Cu/Ni system are nearly axial symme tric (g(parallel to) = 2.122, g(perpendicular to) = 2.0281 A(parallel to)(C u) = -159 (.) 5(.)10(-4) cm(-1), A(perpendicular to)(Cu) = -36.9 (.) 10(-4) cm(-1)). The coordination geome try of the Cu-II guest complex in the tetr ahedral Cu/Zn system is rather distorted, which is shown by the changed g a nd A(Cu) tenser parameters (g(parallel to) = 2.143, g(perpendicular to) = 2 .042, A(parallel to)(Cu) = -103.0 (.) 10(-4) cm(-1), A(perpendicular to)(Cu ) = -5.0 (.) 10(-4) cm(-1)). The spin density distribution is discussed usi ng EHT molecular orbital calculations.