Synthesis and Structural Characterization of Neutral Higher‐Coordinate Silicon(iv) Complexes with Tridentate Dianionic Chelate Ligands

Abstract

The neutral pentacoordinate silicon(IV) complexes 8 and 9 with an SiO2N3 skeleton and the neutral hexacoordinate silicon(IV) complex 10.1/2 CH3CN with an SiO4N2 skeleton were synthesized, starting from tetra(cyanato-N)silane or tetra(thiocyanato-N)silane. Compounds 8 and 9 contain one tridentate dianionic ligand derived from 4-[(2-hydroxyphenyl)amino]pent-3-en-2-one and two monodentate singly charged cyanato-N or thiocyanato-N ligands bound to the silicon(IV) coordination center, whereas the silicon(IV) center of 10 is coordinated by two of these tridentate dianionic ligands. All compounds were characterized by single-crystal X-ray diffraction and solid-state and solution NMR spectroscopy. To get more information about the stereochemistry of the compounds studied, the experimental investigations were complemented by computational studies.

Silicon(IV) Chelates of an (ONN')-Tridentate Pyrrole-2-Carbaldimine Ligand: Syntheses, Structures and UV/Vis Properties

“…The largest difference is found for the Si-N I bond (0.023Å). This behavior is in accord with recent findings by Seiler et al [12]. Because of the planarity of the tridentate ligand L 2− the ax-eq-ax positions of the distorted trigonal bipyramid are occupied in LSiPh 2 , while a mer arrangement results for L 2 Si.…”

Synthesis and Structural Characterization of Novel Neutral Hexacoordinate Silicon(IV) Complexes with SiS2O2N2 Skeletons

“…The hexacoordinate silicon(IV) complex 1 was synthesized by treatment of tetra(cyanato‐ N )silane [Si(NCO) 4 ] with two molar equivalents of 4‐[(2‐hydroxyphenyl)amino]pent‐3‐en‐2‐one 8a. Literature reports concerning the corresponding sulfur analogue, 4‐[(2‐mercaptophenyl)amino]pent‐3‐en‐2‐one, and related compounds are rather confusing 7,12.…”

Neutral Lewis Base Adducts of Silicon Tetraazide

“…Compounds 2 and 3 ⋅0.5 MeCN were characterized by elemental analyses, IR spectroscopy, multinuclear NMR spectroscopy, and single‐crystal X‐ray diffraction (Figures 2 and 3). 13 The molecular structures reveal the presence of distorted‐octahedral λ 6 silicon complexes 17. The distortion of the coordination polyhedron results mainly from the bite angle of the chelating ligands bpy (81.20(6)°) and phen (81.81(5)°).…”