Structural trends in group 4 metal tetraaza macrocycle complexes. Molecular structures of (Me{sub 4}taen)Zr(O{sup t}Bu){sub 2} and (Me{sub 4}taen)Hf(NMe{sub 2}){sub 2}
- Univ. of Iowa, Iowa City, IA (United States)
- Univ. of Alabama, Tuscaloosa, AL (United States)
The tetraaza macrocycle complexes (Me{sub 4}taen)Zr(O{sup t}Bu){sub 2} (4) and (Me{sub 4}taen)Hf(NMe{sub 2}){sub 2} (5) have been prepared and characterized by X-ray crystallography. Both species adopt cis structures with distorted octahedral metal geometries. These structures are similar to that observed earlier for (Me{sub 4}taen)Zr(NMe{sub 2}){sub 2} (3) but quite different from the trigonal prismatic structures observed for (Me{sub 4}taen)ZrCl{sub 2} (1) and (Me{sub 4}taen)Zr(CH{sub 2}Ph){sub 2} (2). The structures of these d{sup 0} (Me{sub 4}taen)MX{sub 2} species are rationalized on electronic grounds. The conformational properties of the Me{sub 4}taen{sup 2-} macrocycle and the covalent character of and absence of a strong {pi}-component in the M-X bonds favor trigonal prismatic structures for 1 and 2, whereas M-X {pi}-bonding in 3-5 promotes distortion toward octahedral structures. Compound 4, C{sub 22}H{sub 40}N{sub 4}O{sub 2}Zr, crystallizes in the triclinic space group P{bar 1} with a = 9.6080- (8) {angstrom}, b = 9.7407(8) {angstrom}, c = 14.5916(12) {angstrom}, {alpha} = 92.714(1){degrees}, {beta} = 107.808(1){degrees} {gamma} = 99.810(1){degrees}, and Z = 2. Compound 5, C{sub 18}H{sub 34}N{sub 6}Hf{center_dot}0.5(C{sub 7}H{sub 8}), crystallizes in the triclinic space group P{bar 1} with a = 9.102(3) {angstrom}, b = 11.242-(4) {angstrom}, c = 13.478(5) {angstrom}, {alpha} = 108.672(5){degrees}, {beta} = 96.310(5){degrees}, {gamma} = 106.266(6){degrees}, and Z = 2.
- DOE Contract Number:
- FG02-88ER13935
- OSTI ID:
- 518390
- Journal Information:
- Inorganic Chemistry, Vol. 36, Issue 1; Other Information: PBD: 1 Jan 1997
- Country of Publication:
- United States
- Language:
- English
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