Tetranuclear Strontium and Barium Siloxide/Amide Clusters in Metal‐Ligand Cooperative Catalysis

Abstract

One-pot reaction of 2,6-iPr 2 -aniline (DIPP-NH 2 ) with (Me 2 SiO) 3 and Sr[N(SiMe 3 ) 2 ] 2 (SrN′′ 2 ) gave a tetranuclear cluster consisting of four dianions [OSiMe 2 N-DIPP] 2and four Sr 2+ ions solvated each by one THF ligand. The general applicability of this method was investigated by variation of amine and metal. Anilines with smaller substituents led to insoluble uncharacterized coordination polymers, whereas bulkier anilines gave soluble product mixtures that could not be purified. Primary alkylamines neither led to isolable products. Introduction of a tBu group in para-position of DIPP-NH 2 , however, gave an isostruc- [a]

Barium Siloxides and Catalysed Formation of Si−O−Si' Motifs

“…Yet, they are either stabilized by solvento rm acrocyclic donors, as in [Ba 3 (OSiPh 3 ) 6 .thf]·(thf) 1/2 , [7] [Ba(OSiPh 3 ) 2 (15-crown-5)·thf] [8] [Ba 2 (OSitBu 3 ) 4 ·thf], [9] and [Ba 3 (OSiPh 2 OSiPh 2 O) 3 (tetraglyme) 2 ], [10] or the siloxide is the anionic part of am ultidentate ligand. [11,12] To our knowledge, no occurrence of solvent-free, unsupported Ba-siloxidei sk nown to date.[a] E.…”

“…Rhodium(I) compounds [24] and [AuCl(PPh 3 )] [25] catalyset he coupling of tertiary silanols with hydrosilanes. [Ru 3 (CO) 12 ]a llows for the one-pot functionalization of polyhedral oligomeric silsesquioxanes (POSS) upon coupling of hydrosilanes with POSSsilanols. [26] In addition, the coupling of silanols with alkoxysilanes promoted by B(C 6 F 5 ) 3 also yields siloxanes [27,28] and can be used to synthesise oligosiloxanes.…”

Alkaline Earth Metal Template (Cross‐)Coupling Reactions with Hybrid Disila‐Crown Ether Analogues

“…Nonetheless, the coordination chemistry turned out to be very suitable for early Group 1 and 2 metal ions, especially within disila‐ligands, which provide more suitable bite angles than cyclosiloxanes of D n type (D=Me 2 SiO, n =6, 7) . The nature of a cation, which shall be complexed within siloxane moieties, is preferably hard . In the case of the early alkaline earth‐metal ions, even the commercially available cyclosiloxanes are able to dissolve salts characterized by a high lattice energy and stable complexes were obtained .…”

“…[22][23][24][25][26] The nature of ac ation, which shall be complexed within siloxane moieties, is preferably hard. [13,[27][28][29][30][31] In the case of the early alkaline earth-metal ions, even the commerciallya vailablec yclosiloxanes are able to dissolve salts characterized by ah igh lattice energy and stable complexes wereo btained. [32] Soft cations like Rb + + and Cs + + so far relucteds ilyl ether coordination.…”

“…HNMR (300 MHz, CD2 Cl 2 ): d = 0.44 (s, 12 H, Si(CH 3 ) 2 ), 0.47 (s, 12 H, Si(CH 3 ) 2 ), 0.56 (s, 12 H, Si(CH 3 ) 2 ), 3.96 ppm (s, 8H,C H 2 ); 13 C{ 1 H} NMR d = À0.5 (s, Si(CH 3 ) 2 ), À0.5 (s, Si(CH 3 ) 2 ), 4.1 (s, Si(CH 3 ) 2 ), 65.3 (s, CH 2 ), 65.4 ppm (s, CH 2 ); 29 Si{ 1 H} NMR (60 MHz, CD 2 Cl 2 ): d = 13.3 (s, Si(CH 3 ) 2 ), 19.3 (s, Si(CH 3 ) 2 ), 19.4 ppm (s, Si(CH 3 ) 2 ). MS:E SI(+ +) m/z (%): 698.9902 [MÀI] + + (100), 507.1697 [MÀSrI 2 + +Na] + +(30).…”