Reduction of Borazines Mediated by Low‐Valent Chromium Species

Abstract

Erholung für erschöpftes BN: Das {Cr(CO)3}‐Komplexfragment vermittelt die Reduktion von Borazinen durch Hydrid‐ und Methyl‐Nucleophile unter Bildung anionischer Komplexe von desaromatisiertem Hexamethylborazin. Anschließend kann das substituierte Cyclotriborazan freigesetzt werden. In diesem System wurde die stufenweise Reduktion einer BN‐Bindung belegt.

Tris(3,5‐dimethylpyrazolyl)methane‐Based Heterobimetallic Complexes that Contain Zn and CdTransition‐Metal Bonds: Synthesis, Structures, and Quantum Chemical Calculations

“…(204.7 pm), [15] [MgBr(thf) 4 {6-[(Me 6 B 3 N 3 )Cr(CO) 3 }] (207.9 pm), [23] and [Mg(thf) 2 {m-Cym*C(BC 4 Ph 4 ) 2 }Mg(thf) 3 ] (219.4 pm). [24] In good agreement with the IR spectroscopic data, the atomic distances of the CÀ O bonds in the isocarbonyl bridges (average bond length = 120.8 (3 a) and 119.6 pm (3 b)) are approximately 3 pm longer than in the terminal CO ligands (average bond length 116.9 (3 a) and 117.1 pm (3 b)).…”

“…[21] Instead, the formation of MgÀisocarbonyl complexes is preferred, as already described. [10,22] [10] [MgBr(thf) 4 {6-[(Me 6 B 3 N 3 )Cr(CO) 3 }] (ñ = 1763, 1694 cm À1 ; KBr), [23] and [Mg(thf) 2 {m-Cym*(BC 4 Ph 4 ) 2 }Mg(thf) 3 ] (ñ = 1774 cm À1 ; ATR, Cym* = {(OC) 3 Mn(h 5 -C 5 H 3 )}). [24] To confirm these assignments, the structures of 3 a/b* were optimised and the corresponding IR vibrations calculated by using DFT methods (RI-DFT/BP86-D3/def2-TZVPP).…”