(6,17-Dimethyl-8,15-diphenyldibenzo[b,i][1,4,8,11]-tetra-aza[14]annulenato)nickel(II) in solids: two guest-free polymorphs and inclusion compounds with methylene chloride and fullerene (C(60))-carbon disulfide

Two guest-free polymorphs and two inclusion compounds of the macrocyclic title complex NiL] have been isolated and characterized with single-crystal and/or powder XRD, solid-state (13)C NMR, and other methods. The inclusion compound with methylene chloride, NiL](CH(2)Cl(2)), is stable in air and thermally stable up to approximately 128 degrees C. Its crystal structure is consistent with van der Waals packing of the host NiL] and guest CH(2)Cl(2) molecules. The host complex has square-planar coordination of the nickel(II) center with four nitrogen atoms of the macrocycle with an average Ni-N distance of 1.86 A. The molecule has a saddle-shaped conformation with the guest molecule located between one phenylene and two phenyl rings of the host molecule. Isostructural compounds with chloroform and 2-chloropropane form only as mixtures along with a guest-free host polymorph. The inclusion compound with C(60) has a composition 3NiL]*(C(60))*2(CS(2)) and here also the crystal structure is consistent with a van der Waals type of packing. Three crystallographically inequivalent NiL] molecules have geometries similar to that in the inclusion compound with methylene chloride. The concave surfaces of the complex molecules form a spherical cavity for the C(60) molecule. At -100 degrees C the C(60) molecule is disordered over two orientations centered at the same site. (13)C NMR studies at room temperature show that the C(60) molecule is undergoing rapid pseudo-isotropic rotation. The stability and other properties of the title and related complexes are discussed.