New tetraazaannulene hosts for fullerenes

Inorg Chem. 2010 Jun 7;49(11):5120-5. doi: 10.1021/ic1002513.

Abstract

Two modifications to the doubly concaved host molecules based on well-known nickel tetraazaannulene complexes have resulted in the preparation of the compounds Ni(NapTMTAA).2benzene, 1,6,8,15,17-tetramethyldinapthalene-5,9,14,18-tetraazacyclotetradecinatonickel(II), and Ni(Cl(4)TMTAA).CH(2)Cl(2), 2,3,11,12-tetrachloro-6,8,15,17-tetramethyldibenzo-5,9,14,18-tetraazacyclotetradecinatonickel(II). When crystallized with C(60) in carbon disulfide, the crystalline, well-ordered, host-guest compounds Ni(NapTMTAA).C(60).2CS(2) and Ni(Cl(4)TMTAA).C(60).2CS(2) were formed. The compounds were characterized by X-ray crystallography. The crystal structures of the precursor host molecules showed very strong host-host interactions, particularly in the case of Ni(Cl(4)TMTAA), which had short Ni...Ni interactions of 3.3860(11) and 3.5888(11) A in the two different dimers in the asymmetric unit; yet, these host-host interactions were entirely destroyed in the resultant host-guest compounds, and C(60) molecules were shown to make use of both cusps of the host macrocycle in the formation of a shape-selective arrangement.