Synthesis, Structural, Spectroscopic, and Magnetic Characterization of Two-Coordinate Cobalt(II) Aryloxides with Bent or Linear Coordination
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- 作者：Aimee M. Bryan ; Gary J. Long ; Fernande Grandjean ; Philip P. Power
- 刊名：Inorganic Chemistry
- 出版年：2014
- 出版时间：March 3, 2014
- 年：2014
- 卷：53
- 期：5
- 页码：2692-2698
- 全文大小：305K
- 年卷期：v.53,no.5(March 3, 2014)
- ISSN：1520-510X
文摘
Treatment of the cobalt(II) amide, [Co{N(SiMe3)2}2]2, with four equivalents of the sterically crowded terphenyl phenols, HOArMe6 (ArMe6 = C6H3-2,6(C6H2-2,4,6-Me3)2) or HOAriPr4 (AriPr4 = C6H3-2,6(C6H3-2,6-Pri2)2), produced the first well-characterized, monomeric two-coordinate cobalt(II) bisaryloxides, Co(OArMe6)2 (1) and Co(OAriPr4)2 (2a and 2b), as red solids in good yields with elimination of HN(SiMe3)2. The compounds were characterized by electronic spectroscopy, X-ray crystallography, and direct current magnetization measurements. The O鈥揅o鈥揙 interligand angles in 2a and 2b are 180掳, whereas the O鈥揅o鈥揙 angle in 1 is bent at 130.12(8)掳 and its cobalt(II) ion has a highly distorted pseudotetrahedral geometry with close interactions to the ipso-carbons of the two flanking aryl rings. The Co鈥揙 distances in 1, 2a, and 2b are 1.858(2), 1.841(1), and 1.836(2) 脜 respectively. Structural refinement revealed that 1, 2a, and 2b have different fractional occupations of the cobalt site in their crystal structures: 1, 95.0%, 2a, 93.5%, and 2b, 84.6%. Correction of the magnetic data for the different cobalt(II) occupancies showed that the magnetization of 2a and 2b was virtually identical. The effective magnetic moments for 1, 2a, and 2b, 5.646(5), 5.754(5), and 5.636(3) 渭B respectively, were indicative of significant spin鈥搊rbit coupling. The differences in magnetic properties between 1 and 2a/2b are attributed to their different cobalt coordination geometries.