Reactivity of a Silylsilylene Bearing a Functionalized Diaminochlorosilyl Substituent

Abstract

The reactivity of the silylsilylene [{PhC(NtBu)(2)}SiSi(Cl){(NtBu)(2)C(H)Ph}] (2) towards diphenylacetylene, azobenzene, 2,6-diisopropylphenyl azide, sulfur, and selenium is described. The reaction of 2 with one equivalent of azobenzene in toluene afforded compound 3, which is the first example of a 1,2-diaza-3,4-disilacyclobutane containing a pentacoordinate silicon center. The formation of 3 can be explained by a [1+2] cycloaddition of the divalent Si center in 2 with PhN=NPh to form a diazasilacyclopropane intermediate, which then undergoes a 1,2-chlorine shift to release the ring strain to form 3. Similarly, the reaction of 2 with one equivalent of diphenylacetylene in toluene afforded the 1,2-disilacyclobutene 4, which contains a pentacoordinate silicon center. The reaction of 2 with 1.6 equivalents of 2,6-diisopropylphenylazide in toluene afforded the silaimine [LSi(=NAr)N(Ar)L'] (5, L=PhC(NtBu)(2) , L'=Si(Cl){(NtBu)(2)C(H)Ph}, Ar=2,6-iPr(2)C(6)H(3)). The formation of 5 can be explained by an oxidative addition of the divalent Si center in 2 with ArN(3) to afford a silaimine intermediate, which then reacts with another molecule of ArN(3) to give compound 5. The reaction of 2 with elemental sulfur in toluene afforded the chlorosilanethione [LSi(S)Cl] (6) and dithiodisiletane [{Ph(H)C(NtBu)(2) }Si(μ-S)](2) (7). Treatment of 2 with elemental selenium in THF afforded the di(silaneselone) [LSi(Se)Si(Se)L] (8). Evidently, the divalent Si center in 2 undergoes oxidative addition with chalcogens to afford a silylsilanechalcogenone intermediate, which then displaces ":Si{(NtBu)(2)C(H)Ph}" and "ClSi{(NtBu)(2) C(H)Ph}" to form 6 and 8, respectively. Moreover, compound 8 was synthesized by the reaction of [{PhC(NtBu)(2)}Si:](2) (10) with elemental selenium in THF. The results show that the reactions of 2 are initiated by oxidative addition of the divalent silicon center, and then the intermediate formed undergoes a rearrangement involving the diaminochlorosilyl substituent to form compounds 3-8. These products have been characterized by NMR spectroscopy and X-ray crystallography.

Stable Five‐Coordinate Silicon(IV) Complexes with SiN4X Skeletons (X=S, Se, Te) and SiX Double Bonds

“…square pyramid) amount to 18.9/14.8 % (11 a), 17.5 % (11 b), and 15.3 % (11 c). [3][4][5][6][7][8][9][10] This slight increase is in line with the change of the silicon coordination number from three or four to five. These Si À X bond lengths are slightly longer than those of the three-and four-coordinate sili-A C H T U N G T R E N N U N G con(IV) compounds with Si=X double bonds described in the literature.…”

A soluble molecular variant of the semiconducting silicondiselenide

“…To the best of our knowledge, this is the first report on a neutral ligand-stabilized molecular Si 2 Se 4 species. 18,19 …”

An Intramolecular Silylene Borane Capable of Facile Activation of Small Molecules, Including Metal‐Free Dehydrogenation of Water

“…Complex 2 represents the first structurally characterized Ga-NHSi complex. TheS i =Sd istance of 1.9795(10) is akin to related silanthiones with four-coordinate silicon atoms [{PhC(N t Bu) 2 }Si(S)Cl] (2.079(6) ) [16] and IPr 2 Me 2 ! [13] With 1 in hand we investigated its reactivity towards dioxygen.…”