Reaction of Early Transition Metal Complexes With Macrocycles III. Synthesis and Structure of 18-Crown-6·l₄(M = Ti, Sn)

Abstract

Abstract 18-Crown-6 reacts with either TiCl4 or SnCl4 in toluene to form an addition complex in which the macrocycle functions as a bidentate ligand. The two compounds are isostructural and belong to the monoclinic space group P21/n. For Ti. the cell parameters are a = 10.501(6), b = 18.104(5), c = 10.955(5) Å, β = 109.76(3)°, and Dc = 1.55 g/cm3 for Z = 4; for Sn, a = 10.572(9), b = 18.139(6), c = 11.056(5) Å, β = 109.16(4)°, and Dc = 1.75 g/cm3. Least-squares refinement led to a final R = 0.037 for 1735 observed reflections for the Ti complex, and R = 0.038 for 2940 observed reflections for the Sn derivative. The M-Cl lengths range from 2.221(2)–2.285(2) Å for M = Ti, and from 2.353(2)–2.357(2) Å for M = Sn. The M—O bonds are 2.102(4) and 2.138(4) Å for M = Ti, and 2.212(4) and 2.237(4) Å for M = Sn.