In situ formed Li/Cl phosphinidenoid complexes [Li(12-crown-4)][M(CO)5(ClPC5Me5)] 3a–c (M = Cr, Mo, W) reacted with cyclobutanone (4), cyclopentanone (5) and cyclohexanone (6) in Et2O to yield the first P-C5Me5 substituted C3-spirofused oxaphosphirane complexes 7a–c, 8a and 9a,a′. In the case of cyclopentanone and 1a the outcome of the reaction in THF was different: here the formation of 8a along with (anionic) phosphinoate complexes 14a and 15a was observed, the latter possess an unusual ring-opened oxaphosphirane and 2-cyclopentylidenecyclopentanone as co-ligands to the lithium cation. NMR, IR and MS data as well as single-crystal X-ray structures in the case of 7a–c, 8a, 9a and 15a are reported. DFT calculations on the parent 1-oxa-2-phosphaspiro[2.n]alkane pentacarbonylchromium(0) complexes 10 (a: n = 2; b: n = 3; c: n = 4; d: n = 5) revealed that both ring strain energies and G(r) values decrease significantly as the spiroring size increases. This is caused by an increase in the exocyclic α bond angle at the oxaphosphirane C3 atom, hence decreasing the s-character of the corresponding orbitals involved in endocyclic bonds at C3 and thus becoming better suited for accommodation of small ring angles.
原位形成的 Li/Cl 膦类络合物 [Li(12-crown-4)][M(CO)5(ClPC5Me5)] 3a–c (M = Cr, Mo, W) 与
环丁酮 (4)、
环戊酮 (5) 反应) 和
环己酮 (6) 在 Et2O 中生成第一个 P-C5Me5 取代的 C3-螺稠氧杂
磷烷配合物 7a–c、8a 和 9a,a'。对于
环戊酮和 1a,在 THF 中的反应结果不同:这里观察到 8a 与(阴离子)
次膦酸酯配合物 14a 和 15a 一起形成,后者具有不寻常的开环氧杂膦和 2-亚环戊基
环戊酮作为配合物。 -
锂阳离子的
配体。报告了 7a-c、8a、9a 和 15a 的 NMR、IR 和 MS 数据以及单晶 X 射线结构。对母体 1-oxa-2-phosphaspiro[2.n]alkane pentacarbonylchromium(0) 配合物 10(a:n = 2;b:n = 3;c:n = 4;d:n = 5)的 DFT 计算表明随着螺环尺寸的增加,环应变能和 G(r) 值均显着降低。这是由于氧杂
磷杂环 C3 原子处的环外 α 键角增加,从而减少了 C3 处环内键所涉及的相应轨道的 s 特征,从而更适合调节小环角。