Molecular structure of o-phenylene sulphite, an electron diffraction study

The Structure of Bis(catecholato)silanes: Phase Adaptation by Dynamic Covalent Chemistry of the Si–O Bond

“…The 29 Si MAS NMR provided a shift of −150.3 ppm (Figure 3a), lying in the expected range for hexacoordinated silicon. 15 This chemical shift is consistent with the DFT-computed value of −147.0 ppm for trans-3• (CH 3 CN) 2 (PBE0/TZ2P, see SI) and confirms our previous The 29 Si MAS NMR spectrum of a sublimed sample of 2 displayed a sharp singlet at −40.7 ppm (Figure 3b). This shift agrees with the DFT-computed value for monomeric, tetrahedral 2 (−38.2 ppm, Figure 4c), and represents the first spectroscopic evidence for a monomeric bis(catecholato)silane.…”

“…At 1.388(2) Å ( 1 ) and 1.395(4)/1.390(4) Å ( 2 ), they are longer than in PhOSiH 3 (1.357(9) Å) and H 2 CCHOSiMe 3 (1.355(6) Å), also with planar coordinate carbon atoms, but shorter than in H 3 COSiH 3 (1.418(9) Å) and Si­(OMe) 4 (1.416(2) Å) with tetracoordinate carbon atoms. Yet, the determined C–O distance falls within the range of other catecholato substituted main group compounds of the third row ((cat H )­P­(O)­Cl, r a = 1.420(20) Å; (cat H )­S­(O), r a = 1.401(9) Å).…”

“…Surprisingly, 1 H and 13 C{ 1 H} NMR spectra of 1 in CD 2 Cl 2 revealed a mixture of multiple compounds (Figure 2a). 14 However, the identical product batch of 1 in THF-d 8 (Figure 2b), or the addition of Et 3 PO to the very same sample, yielded spectra associated with single compounds, unequivocally identified as the respective Lewis adducts 1•(THF) 2 and 1•(OPEt 3 ) by 29 Si NMR and single-crystal X-ray diffraction (see Supporting Information (SI) section 2.1 and literature). 13c…”

“…MAS NMR and Vibrational Spectroscopy: Structure in the Solid State. The limited solubilities of bis(catecholato)silanes were hampering solution-phase 29 Si NMR spectroscopy in previous studies. 13a−c Hence, the solid powders 1, 2, and 3• (CH 3 CN) 2 were investigated by 29 Si MAS NMR spectroscopy.…”

“…The limited solubilities of bis(catecholato)silanes were hampering solution-phase 29 Si NMR spectroscopy in previous studies. 13a−c Hence, the solid powders 1, 2, and 3• (CH 3 CN) 2 were investigated by 29 Si MAS NMR spectroscopy. We start the discussion with the compound of proposed composition 3•(CH 3 CN) 2 .…”