Reactivity of Bis(η⁶‐benzene)chromium(0) toward Sulfur Dioxide: Formation and Structure of [(η⁶‐C₆H₆)₂Cr]₂S₄O₁₀, a Salt Containing the Anion [S₂O₆·2SO₂]^2⊖

A new combination of donor and acceptor: bis(η6-benzene)chromium and hexafluorobenzene form a charge-transfer stacked crystal

“…The solutions from reaction of 1 with C 6 F 6 (whether dilute or more concentrated) gave a broad EPR signal at g = 1.987 consistent with formation of [Cr(h 6 -C 6 H 6 ) 2 ] + 1 + . 6 Solid-state EPR spectra of the yellow precipitate from reaction of 1 with C 6 F 6 also revealed the presence of 1 + (g || = 2.002, g ^= 1.983), while IR spectra showed characteristic bands of both 1 and 1 + . 17 The presence of fluoride as a corresponding anion was revealed by its reaction with Me 3 SiOTf yielding Me 3 SiF.∑ In order to ascertain the proportion of 1 which is oxidised, we investigated the effect of addition of C 6 F 6 to toluene solutions of 1.…”

“…3 Complex analogues of C 6 H 6 •C 6 F 6 are attracting interest for their optoelectronic properties. 4,5 Bis(h 6 -benzene)chromium 1 has potential for both these types of interaction: it has featured as a donor in [Cr(h 6 -C 6 H 6 ) 2 ][S 2 O 6 •2SO 2 ] and has been employed for crystal engineering. 6,7 Donor-acceptor (DA) complexes are also formed by 1 in [Cr(h 6 -C 6 H 6 ) 2 ][TCNE] and [Cr(h 6 -C 6 Me 3 H 3 ) 2 ][TCNQ] but they are arranged in stacks of the type •••A 2 DD••• or in chains.…”

“…4,5 Bis(h 6 -benzene)chromium 1 has potential for both these types of interaction: it has featured as a donor in [Cr(h 6 -C 6 H 6 ) 2 ][S 2 O 6 •2SO 2 ] and has been employed for crystal engineering. 6,7 Donor-acceptor (DA) complexes are also formed by 1 in [Cr(h 6 -C 6 H 6 ) 2 ][TCNE] and [Cr(h 6 -C 6 Me 3 H 3 ) 2 ][TCNQ] but they are arranged in stacks of the type •••A 2 DD••• or in chains. 8 Several authors have proposed that an electron-transfer process precedes C-F bond activation of perfluoroalkanes and perfluoroarenes by transition metal complexes, [9][10][11] although experimental support for redox initiation is sparse.…”

The Preparation of (η5-C5Me5)Ir(PMe3)S4from (η5-C5Me5)Ir(PMe3)(SH)2and SO2

“…The formation of sulfato complexes has been observed previously via unusual reactions, such as that 7c between SO 2 and Ru(H) 2 (PR 3 ) x , where x = 3 or 4, to give Ru(SO 4 )(SO 2 )(PPh 3 )(H 2 O) wherein SO 2 disproportionation was proposed. SO 2 reacted with (η 6 -C 6 H 6 ) 2 Cr to give the salt [η 6 -C 6 H 6 ) 2 Cr]S 4 O 10 , which contains the anion S 2 O 6 ·2SO 2 2- . The complex (dppe) 2 Mo(N 2 ) 2 reacted with SO 2 to give trans -(dppe) 2 Mo(S)O, the crystal structure of which contained SO 2 and H 2 SO 4 in stoichiometric proportion in the lattice.…”