Thermal, optical and structural properties of disulfide and diselenide salts with weakly associated anions

Saturated NHC Derived Dichalcogen Dications

“…Compounds 3a‐S and 3b‐S are pale yellow solids and thus their UV/Vis spectra show no (for 3a‐S ) or a very weak (at 490 nm for 3b‐S ) absorption in the visible region. The latter is consistent with its UV/Vis absorption (474 nm) measured in the solid‐state . While the UV/Vis spectrum of 3a‐Se (orange solid) shows a shoulder at 505 nm, those of 3b‐Se (violet solid), 3a‐Te (violet solid) and 3b‐Te (green solid) measured in acetonitrile exhibit a characteristic broad absorption maximum at 507 nm, 571 nm, and 630 nm, respectively.…”

“…Reaction of a dichloromethane solution of 2a‐E (E = S, Se or Te) each with triflic anhydride (Tf 2 O) yielded compounds 3a‐E as crystalline solids. By employing a similar method, hitherto known compounds 3b‐S and 3b‐Se , are also accessible in 82–92 % yield from (IPr)S ( 1b‐S ) and (IPr)Se ( 1b‐Se ). [15b] While the exact mechanism of the formation of 3a‐E and 3b‐E is currently not known, Tf 2 O seems to serve as one‐electron oxidant to generate triflate anion and [CF 3 SO 2 ] radical.…”

“…Dicationic compounds IV-E (E = S, Se or Te) obtained by the oxidative E-E coupling of the corresponding N-heterocyclic ketones (NHKs) II-E can be regarded as structural diatomic analogues of neutral compounds III-E. Indeed, several compounds IV-E (E = S, [12] Se, [12] and Te [13] ) also based on a similar unsaturated bulky NHC (IPr = C{(NDipp)CH} 2 ; Dipp = 2,6-iPr 2 C 6 H 3 ) have been isolated. Nonetheless, compounds IV-S and IV-Se were characterized by elemental analysis, IR spectroscopy, and X-ray diffraction but no NMR spectroscopic data was provided.…”

Facile Access to Diselenide Containing Macrocyclic Ring from Diselone

“…The distance between Se(1) to Se(1) is 7.839 Å. The Se−Se bond length in 5 is (2.345(3) Å) slightly shorter than that of previously reported diselenide dications, [{IPrSe} 2+ (OTf) 2− ] 2 (2.427(5) Å), [(mims) 2 (cctc)] n (2.3946(13) Å; mims ‐ N,N’‐methyl‐imidazole‐selenide; cctc ‐ μ 3 ‐chlorido‐tetra‐ μ 2 ‐chlorido‐tricuprate(I)]), [2(ebis) 2 ][2(TCNQ) 3 ] (2.451(2) Å; TCNQ ‐ tetracyanoquino‐dimethane and ebis ‐ bis(selenoimidazolyl)ethane, [(mims) 2 ]Br 2 (2.409(2) Å), [(mims) 2 ]I 2 (2.434(2) Å), [(mims) 2 Cl]I 3 (2.440(2) Å), [(mims’) 2 Br](IBr 2 ) (2.424(1) Å; ; mims’ ‐ N,N’‐methyl‐imidazole‐selenide), [(MeN(CH) 2 NCH 2 )CSe} 2 I 3 ]( I 4 ) (2.416(2) Å), [{(bbims) 2 } 2 {FeCl 4 } 3 Cl] (2.410(1) Å; bbims ‐ 1,3‐dibutylbenzimidazol selone), [{(ipbms) 2 }{(FeCl 4 )Cl}] (2.423(1) Å; ipbms ‐ 1,3‐diipropylbenzimidazol‐selone), [{(ipbms) 2 }{(FeBr 4 )Br}] (2.433(1) Å), [{(bbims) 2 }X] [X={ZnCl 3 (H 2 O) 2 } 2 (2.363(1) Å), {ZnBr 4 } (2.377(1) Å)] and [{(bbims) 2 }{Hg 2 Cl 6 }] (2.361(1) Å) . 5 is packed in a column structure and interaction between columns are absent (Figure (III)).…”

“…The first triflate salt of 1,3‐disubstituted imidazole diselenide dication was derived using Cu(OTf) 2 . Later, the oxidative reaction of sterically crowded IPrSe or IPr'Se (IPr={(HCN(C 6 H 3 ‐ i Pr 2 ‐2,6)) 2 C}; IPr’=[(HC) 2 {N(C 6 H 3 ‐ i Pr 2 ‐2,6)}{NCH 2 C(O)OMe}C}] by Bi(OTf) 3 or Cu(ClO 4 ) 2 ⋅6H 2 O was reported to isolate [(IPr) Se] 2 2+ { ‐ OTf} 2 ] or [(IPr‘)Se] 2 2+ { ‐ O 4 Cl} 2 ], respectively . Recently, sixteen new examples of imidazole diselenide dications were reported using different transition metal salts as oxidizing agent .…”