Two polymorphs of a lead(II) complex with 8-hydroxy-2-methylquinoline and thiocyanate.

Two distinct polymorphs of bis(mu(2)-methylquinolin-8-olato)-kappa(3)N,O:O;kappa(3)O:N,O-bis[(isothiocyanato-kappaN)lead(II)], [Pb(2)(C(10)H(8)NO)(2)(NCS)(2)], (I), forming dinuclear complexes from a methanolic solution containing lead(II) nitrate, 2-methylquinolin-8-ol (M-Hq) and KSCN, crystallized concomitantly as colourless prisms [form (Ia)] and long thin colourless needles [form (Ib)]. In both cases, the complexes lie across a centre of inversion. The polymorphs differ substantially in their conformation and in their interactions, viz. Pb...S and pi-pi for form (Ia) and Pb...S, Pb...pi and C-H...pi for form (Ib).