Titanium Germylidenes

• Published in: Angewandte Chemie International Edition 2021-02, Vol.60 (8), p.3951-3955
• Main Authors: Lee, Vladimir Ya, Sakai, Ryo, Takanashi, Kazunori, Gapurenko, Olga A., Minyaev, Ruslan M., Gornitzka, Heinz, Sekiguchi, Akira
• Format: Article
• Language: English
• Subjects: Chemical Sciences; Coordination chemistry; density functional calculations; Germanium; Heavy metals; NMR spectroscopy; Titanium; X-ray diffraction
• ISSN: 1433-7851; 1521-3773
• DOI: 10.1002/anie.202015704

Two novel 18‐electron titanium germylene complexes, Cp2Ti(L)=Ge[Si3(SiMetBu2)4] 3 b (L=Me3P) and 3 c (L=XylNC), were synthesized, isolated, and structurally characterized. The length of the titanium‐germanium bonds of 2.5387(3) Å and 2.5276(3) Å (in 3 b and 3 c, respectively) well match those expected for the double bond, which was further supported by the DFT study. Based on their structural characteristics, as well as their atomic charges calculations which revealed Ti(δ+)=Ge(δ−) bond polarization, both 3 b and 3 c are classified as the Schrock‐type titanium germylidenes, as the germanium analogues of the widely known titanium alkylidenes. By contrast, germylene complexes of the group 6 metals 8 a (M=Mo) and 8 b (M=W) are better described as Fischer‐type germylene complexes. Two novel titanium germylene phosphine and isocyanide complexes, Cp2Ti(L)=Ge[Si3(SiMetBu2)4] (L=Me3P and XylNC), were synthesized and fully characterized. On the basis of their structural characteristics and calculated atomic charges, both complexes are classified as the Schrock‐type titanium germylidenes, as the germanium versions of the widely known titanium alkylidenes.