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• W2007663169 endingPage "5455" @default.
• W2007663169 startingPage "5443" @default.
• W2007663169 abstract "The electronic structures and nature of silicon−chalcogen double bonds Si═X (X = O, S) with four-coordinate silicon in the unique silanoic silylester 2 and silanoic thioester 3 have been investigated for the first time, by 29Si solid state NMR measurements and detailed DFT and ab initio calculations. 29Si solid state NMR spectroscopy of the precursor silylene 1 was also carried out. The experimental and computational study of 2 and 3, which was also supported by a detailed computational study of smaller model systems with Si═O and Si═S bonds, provides a deeper understanding of the isotropic and tensor components of their NMR chemical shifts. The general agreement between the experimental NMR spectra and the calculations strongly support our previous NMR assignment deduced from experiment. The calculations revealed that in 2 δ(29Si(═O))iso is shifted upfield relative to H2Si═O by as much as 175 ppm; the substituents are responsible for ca. 100 ppm of this shift, while the remaining upfield shift is caused by change in the coordination number from three to four at the Si═O moiety. The change in coordination number leads to a nearly cylindrical symmetry in the plane which is perpendicular to the Si═O molecular axis (δ11 ≈ δ22), in contrast to the significant anisotropy found in this plane in typical doubly bonded compounds. The change in r(Si═O) or in the degree of pyramidality at the Si═O center which accompanies the change in coordination number has practically no effect on the chemical shift. δ(29Si(═S))iso in 3 is shifted downfield significantly relative to that in 2, and a similar trend is found in smaller models with Si═S vs those with Si═O subunits. This downfield shift can be explained by the smaller σ−π* energy difference in the Si═S bond, relative to that of the Si═O bond. The NMR measurements of 2 and 3 having a four-coordinate silicon−chalcogen moiety, and the calculations of their tensor components, their bond polarities, and their Wiberg bond indices revealed that the Si═X moieties in both 2 and 3 have a significant π(Si═X) character; yet, in both molecules there is a substantial contribution from a zwitterionic Si+—X− resonance structure, which is more pronounced in 2." @default.
• W2007663169 created "2016-06-24" @default.
• W2007663169 creator A5010680154 @default.
• W2007663169 creator A5031834483 @default.
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• W2007663169 creator A5075148080 @default.
• W2007663169 creator A5083943245 @default.
• W2007663169 date "2010-03-29" @default.
• W2007663169 modified "2023-10-16" @default.
• W2007663169 title "Si═X Multiple Bonding with Four-Coordinate Silicon? Insights into the Nature of the Si═O and Si═S Double Bonds in Stable Silanoic Esters and Related Thioesters: A Combined NMR Spectroscopic and Computational Study" @default.
• W2007663169 cites W1965668416 @default.
• W2007663169 cites W1965743611 @default.
• W2007663169 cites W1966235885 @default.
• W2007663169 cites W1969458034 @default.
• W2007663169 cites W1970368543 @default.
• W2007663169 cites W1971275758 @default.
• W2007663169 cites W1971624144 @default.
• W2007663169 cites W1972274370 @default.
• W2007663169 cites W1973699462 @default.
• W2007663169 cites W1975708211 @default.
• W2007663169 cites W1975944596 @default.
• W2007663169 cites W1976822711 @default.
• W2007663169 cites W1977521713 @default.
• W2007663169 cites W1980625065 @default.
• W2007663169 cites W1981490301 @default.
• W2007663169 cites W1983781224 @default.
• W2007663169 cites W1985542788 @default.
• W2007663169 cites W1986055213 @default.
• W2007663169 cites W1988452685 @default.
• W2007663169 cites W1990617704 @default.
• W2007663169 cites W1993383767 @default.
• W2007663169 cites W1993485326 @default.
• W2007663169 cites W2003560901 @default.
• W2007663169 cites W2004646853 @default.
• W2007663169 cites W2005918561 @default.
• W2007663169 cites W2008281382 @default.
• W2007663169 cites W2010721993 @default.
• W2007663169 cites W2012130053 @default.
• W2007663169 cites W2012350801 @default.
• W2007663169 cites W2012458244 @default.
• W2007663169 cites W2016201764 @default.
• W2007663169 cites W2017813412 @default.
• W2007663169 cites W2020912026 @default.
• W2007663169 cites W2021090826 @default.
• W2007663169 cites W2021295066 @default.
• W2007663169 cites W2023271753 @default.
• W2007663169 cites W2028970781 @default.
• W2007663169 cites W2029954080 @default.
• W2007663169 cites W2030859944 @default.
• W2007663169 cites W2033889724 @default.
• W2007663169 cites W2033990154 @default.
• W2007663169 cites W2035598743 @default.
• W2007663169 cites W2038533471 @default.
• W2007663169 cites W2040807756 @default.
• W2007663169 cites W2042944554 @default.
• W2007663169 cites W2043746850 @default.
• W2007663169 cites W2044940178 @default.
• W2007663169 cites W2045214161 @default.
• W2007663169 cites W2046412723 @default.
• W2007663169 cites W2054164390 @default.
• W2007663169 cites W2054893954 @default.
• W2007663169 cites W2057201905 @default.
• W2007663169 cites W2058432457 @default.
• W2007663169 cites W2060283478 @default.
• W2007663169 cites W2064674762 @default.
• W2007663169 cites W2067769697 @default.
• W2007663169 cites W2069006374 @default.
• W2007663169 cites W2069329659 @default.
• W2007663169 cites W2077703963 @default.
• W2007663169 cites W2081762335 @default.
• W2007663169 cites W2082049547 @default.
• W2007663169 cites W2089395684 @default.
• W2007663169 cites W2091244887 @default.
• W2007663169 cites W2093892775 @default.
• W2007663169 cites W2094642658 @default.
• W2007663169 cites W2107310158 @default.
• W2007663169 cites W2118029354 @default.
• W2007663169 cites W2139728585 @default.
• W2007663169 cites W2143981217 @default.
• W2007663169 cites W2147867735 @default.
• W2007663169 cites W2153687452 @default.
• W2007663169 cites W2156115804 @default.
• W2007663169 cites W2159968793 @default.
• W2007663169 cites W2164318957 @default.
• W2007663169 cites W2170207646 @default.
• W2007663169 cites W2949866219 @default.
• W2007663169 cites W2951321661 @default.
• W2007663169 cites W2951530643 @default.
• W2007663169 cites W2952791608 @default.
• W2007663169 cites W2952957915 @default.
• W2007663169 cites W3005150946 @default.
• W2007663169 cites W4234355526 @default.
• W2007663169 cites W4235494812 @default.
• W2007663169 cites W4239167367 @default.
• W2007663169 cites W4240035468 @default.
• W2007663169 cites W61061905 @default.
• W2007663169 cites W91130287 @default.
• W2007663169 doi "https://doi.org/10.1021/ja1004812" @default.

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