Functionalized Silanols and Silanolates

Abstract

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Silanol-Based Pincer Pt(II) Complexes: Synthesis, Structure, and Unusual Reactivity

“…In the 29 Si NMR spectra (obtained using 29 Si− 1 H HMBC sequence) both complexes 8 and 3 give rise to broadened singlets accompanied by one-bond coupling 195 Pt satellites at δ = 12.27 ppm ( 195 Pt satellites 1 J SiPt = 1190 Hz) and δ = 38.53 ppm ( 195 Pt satellites 1 J SiPt = 1335 Hz), respectively. In the 29 Si-DEPT NMR (which is more sensitive to small coupling constants) of the hydrosilane complex 8 , the mentioned above broadened singlet is resolved into a triplet with 2 J SiP = 5.2 Hz and the same as before 195 Pt satellites, while a 29 Si-INEPT experiment revealed additionally the direct Si−H coupling constant, J SiH = 183 Hz. The diagnostic pattern of the Si−H proton of 8 was observed in both 1 H and 1 H{ 31 P} NMR spectra as a broadened singlet at 5.75 ppm with 195 Pt and 29 Si satellites 2 J HPt = 38.8 Hz, J HSi = 183 Hz.…”

“…In the 29 Si-DEPT NMR (which is more sensitive to small coupling constants) of the hydrosilane complex 8 , the mentioned above broadened singlet is resolved into a triplet with 2 J SiP = 5.2 Hz and the same as before 195 Pt satellites, while a 29 Si-INEPT experiment revealed additionally the direct Si−H coupling constant, J SiH = 183 Hz. The diagnostic pattern of the Si−H proton of 8 was observed in both 1 H and 1 H{ 31 P} NMR spectra as a broadened singlet at 5.75 ppm with 195 Pt and 29 Si satellites 2 J HPt = 38.8 Hz, J HSi = 183 Hz.…”

“…In the 29 Si-INEPT spectrum a large coupling constant with protons, 1 J SiH = 205 Hz, was additionally detected. In the 1 H NMR spectra of 7 the H 2 Si-fragment is observed as a triplet with 29 Si-satellites at δ = 5.45 ppm ( 4 J HP = 8.7 Hz, J HSi = 205 Hz). The hydrosilane fragment in 7 is directly observed in the IR-spectrum as a strong broad band at 2139 cm −1 .…”

“…Organosilanols, silicon compounds of the general formula R n Si(OH) 4− n have been extensively studied . These compounds have found various applications, especially as building blocks for practically important siloxane-type polymers .…”

“…These compounds have found various applications, especially as building blocks for practically important siloxane-type polymers . Metallosiloxanes, complexes of the type Si−O−M derived from silanols, have also attracted considerable interest as precursors for silicone polymers containing metal centers in the polymer backbone, as well as catalysts which structurally mimic metal-modified silica surfaces. , In contrast, metallosilanols, M−Si−OH, represent a relatively new and considerably less studied family of compounds. ,– In most cases the preparations and structural characterizations of these compounds were reported while very little is known about their reactivity.…”