Donor-acceptor substituted disilanes with surprising nonlinear optical effects

Comparison between SiMe2and CMe2Spacers as σ-Bridges for Photoinduced Charge Transfer

“…34 Subsequently amines 18, 19, and 20 were methylated to their quaternary ammonium salts, which were subsequently cleaved by use of ethanolamine (reaction 7). 35 2-(4-Bromophenyl)-2-phenylpropane (21) was obtained by reaction of the diazonium salt of amine 20 with hypophosporous acid (H 3 PO 2 ) (8). 36 Finally, the 4-bromo-substituted diphenylpropanes 12C, 13C, 17, and 21, as well as 4-bromo-tert-butylbenzene, were converted into the corresponding cyanides 1C, 2C, 10C, 5C, and 8C, respectively, using copper(I) cyanide in DMF.…”

“…13 These properties find their origin in the occurrence of σ-conjugation along the silicon backbone, 1,14,15 the presence of polarizable valence electrons, 16 low ionization potentials, 3,14 and σ-π interactions. [17][18][19] Because of these features Zyss and co-workers [20][21][22][23][24][25] investigated the second-order nonlinear optical activity, which is strongly related to the presence of intramolecular CT interactions, of donoracceptor substituted silanes. Although moderate second-order nonlinear optical responses were found, it remained obscure whether CT between donors and acceptors takes place in oligoand especially monosilylene-bridged compounds.…”

Conformation effect of oligosilane linker on photoinduced electron transfer of tetrasilane-linked zinc porphyrin–[60]fullerene dyads

“…Hexane was distilled from sodium/benzophenone/triglym. 1,7-Dichloro-1,7-disilabicyclo[5.5.0]dodecane [21a], 1,2-dichloro-1,1,2,2-tetramethyldisilane [32], 1-(4-bromophenyl)-1,1,2,2-tetramethyl-2-phenyldisilane [33], [5-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-10,15,20-tris[3 0 ,5 0 -(di-tert-butyl)phen-yl]porphinato]zinc(II) (ZnP-Bpin) [34], and [Si 2 ]-C 60 [23] were synthesized as described before. To a solution of 1,7-dichloro-1,7-disilabicyclo[5.5.0] dodecane (Cl-Si 2 (syn)-Cl; 2.…”

Electronic interactions in 1-ethynyl-2-phenyltetramethyldisilanes HCCSiMe2SiMe2C6H4X

“…The Me 2 N-substituted compound 1, however, exhibits a first absorption maximum at 271 nm with unusually high intensity, the position of which is much less affected by the nature of the organosilicon substituent attached to the benzene ring. Thus, going from Me 2 N-C 6 H 4 -SiMe 3 (k max = 266 nm) [14] to 1, a bathochromic shift of just 5 nm is observed, while the first absorption maximum of compound 2, for instance, is shifted to the red by 22 nm as compared to PhSiMe 3 (k max = 211 nm) [4a].…”