Coordination polyhedra of eight-coordinate zirconium complexes and a network built up by crisscross Cl...Cl contacts

Abstract

Two bis(quadridentate) eight-coordinate zirconium complexes, Zr(5-Cldse) 2 (1) [5-Cldse ¼ N,N¢-di(5-chlorosalicylidene)ethylenediamino] and Zr(pida) 2 (2) [pida ¼ N-(2-pyridylmethyl) iminodiacetato], have been prepared and crystallographically characterized. A distorted dodecahedron of N 4 O 4 atoms has been found for the zirconium(IV) center of complexes (1) and (2). A network is constructed in the crystalline state of (1) by crisscross intermolecular ClÁ Á ÁCl contacts (3.45 and 3.43 Å ), which are shorter than the sum of spherical van der Waals radii (3.50 Å ).

Bis{4,4′,6,6′-tetrachloro-2,2′-[trans-(R,R)-cyclohexane-1,2-diylbis(iminomethylene)]diphenolato-κ4O,N,N′,O′}zirconium(IV)

“…Notable bond lengths and angles are listed in Table 1. These bond lengths and angles are similar to those reported in the literature for related bis(salen)zirconium(IV) complexes (Archer et al, 1979;Zhu et al, 2005) (Table 2). In the crystal structure, complex molecules are linked into zig-zag chains running parallel to the (Table 2).…”

“…For examples of eight-coordinate zirconium complexes with related salen-type ligands (salen = N,N 0 -ethylenebis(salicylideneimine), see: Archer et al (1979); Illingsworth et al (2002); Zhu et al (2005). For related literature on salan-type complexes [salan = N,N 0 -ethylenebis(2-hydroxybenzyl)], see: García-Zarracino et al (2002); Yeori et al (2005).…”

“…Whereas titanium(IV) alkoxides, Ti(OR) 4 , coordinate one salcean ligand to yield complexes of the type [salcean]Ti(OR) 2 with the loss of two equivalents of alcohol (Yeori et al, 2005), two equivalents of salcean may displace all four alkoxides from a zirconium(IV) alkoxide, resulting in a distorted dodecahedral eightcoordinate bis(salcean)zirconium(IV) complex, as reported here. Although the structure of no other bis-(salcean)zirconium(IV) complex has been reported, similar eight coordinate zirconium(IV) complexes with salen type ligands exhibiting a distorted dodecahedral coordination sphere are known (Archer et al, 1979;Illingsworth et al, 2001;Zhu et al, 2005).…”