Novel Nucleophilic Reactivity of Disulfido Ligands Coordinated Parallel to M−M (M = Rh, Ir) Bonds

Abstract

Reaction of trans-[(MCp)(2)(mu-CH(2))(2)Cl(2)] (M = Rh, Ir; Cp = eta(5)-C(5)Me(5)) with Li(2)S(2) afforded the disulfido complexes [(MCp)(2)(mu-CH(2))(2)(mu-S(2)-S:S')] which were easily oxidized by O(2) to give the oxygenated complexes [(MCp)(2)(mu-CH(2))(2)(mu-SSO(2)-S:S')]. Although [(RhCp)(2)(mu-CH(2))(2)(mu-S(2)-S:S')] gave a complicated mixture when reacted with CH(2)Cl(2) or CHCl(3), [(IrCp)(2)(mu-CH(2))(2)(mu-S(2)-S:S')] reacted with both CH(2)Cl(2) and CHCl(3) to give the dithioformato complex [(IrCp)(2)(mu-CH(2))(2)(mu-S(2)CH-S:S')]Cl and the cyclotetrasulfido complex [((IrCp)(2)(mu-CH(2))(2))(2)(mu-S(4)-S:S':S":S"')]Cl(2). The oxygenated complexes [(RhCp)(2)(mu-CH(2))(2)(mu-SSO(2)-S:S')] reacted with hydrocarbyl halides to afford bridging hydrocarbyl thiolato complexes accompanied by the generation of SO(2) gas. These complexes have been characterized by NMR spectroscopy, ESI-MS, and X-ray diffraction.

S42− Rings, Disulfides, and Sulfides in Transition‐Metal Complexes: The Subtle Interplay of Oxidation and Structure

“…On the other hand, coordinated S 4 2À most certainly exists, and as we will see, not only as a simple chain (of which Na 2 S 4 is an example [3] ). This paper moves toward an understanding of the variety of complexed S 4 2À structural types and in the process shows that some compounds which hitherto have been considered as disulfide complexes may be profitably seen as containing D 2h -distorted S 4 2À rings. Their formation is attributable to a coupling redox process induced by either an external oxidant or inner oxidation of coordinated metal centers.…”

“…The electronic structure of some compounds in the literature is reinterpreted, and, we believe, there emerges the outline of a consistent way of thinking about redox coupling of sulfides and disulfides.Our analysis was stimulated by the Isobe groups dicationsh 5 -C 5 Me 5 ). [4] In these chair-like complexes, the S 4 rectangle has rather different S···S sides (e.g., 2.049(3) vs. 2.894(3) in 1), the shorter ones being either along (in 1) or across (in 2) the MÀM bonds. Compound 1 is obtained upon 2-e À oxidation of the binuclear precursor [Cp*Ir(m-CH 2 ) 2 (m-S 2 )IrCp*] (3), [4] in which the d 7 metal centers reach saturation with a formal Ir À Ir bond (whose actual length is 2.642(1) ).…”

“…Our analysis was stimulated by the Isobe groups dications [{Cp* 2 M 2 (m-CH 2 ) 2 } 2 (m-S 4 )] 2+ , M = Ir, 1; Rh, 2 (Figure 1, Cp* = h 5 -C 5 Me 5 ). [4] In these chair-like complexes, the S 4 rectangle has rather different S···S sides (e.g., 2.049(3) vs. 2.894(3) in 1), the shorter ones being either along (in 1) or across (in 2) the MÀM bonds. Compound 1 is obtained upon 2-e À oxidation of the binuclear precursor [Cp*Ir(m-CH 2 ) 2 (m-S 2 )IrCp*] (3), [4] in which the d 7 metal centers reach saturation with a formal Ir À Ir bond (whose actual length is 2.642(1) ).…”

Direct Observation of Photochromic Dynamics in the Crystalline State of an Organorhodium Dithionite Complex

“…[4,5] To date, only a limited number of synthetic methodologies and crystalline-state photochromic compounds have been reported, and their photochromic reaction mechanisms and dynamics are not well analyzed as a result of the low degree of isomerization and instability of the photochromic compounds in the solid phase. [6][7][8][9][10] Our coordination-chemistry approach towards the synthesis of new switching-functional molecular crystals using the (RhCp*) 2 (m-CH 2 ) 2 fragment (Cp* = h 5 -C 5 Me 5 ), which can accept two sulfur atoms coordinated parallel to the RhÀRh bond, [11] and the external-stimulusresponsive S 2 O 4 2À ion as ligand [12] led successfully to the formation of uniquely photoresponsive and first side-on dithionite complex [(RhCp*) 2 (m-CH 2 ) 2 (m-O 2 SSO 2 )] (1). Herein we disclose the following two processes in single crystals of 1 (Figure 1): 1) fully reversible crystalline-state photochromism between m-O 2 SSO 2 and m-O 2 SOSO complexes (red), and 2) stereoselective oxygen-atom transfer and stereospecific transformation of the photochemically generated m-O 2 SOSO isomers into the most stable one (blue).…”

Surface-assisted transfer hydrogenation catalysis on a γ-Al2O3-supported Ir dimer

“…31 The isotope-labelled, deuterated complex [Ir 2 {Z 5 -C 5 (CX 3 ) 5 } 2 (m-CH 2 ) 2 ] (X = D (97%) or H (3%), where [Ir 2 {Z 5 -C 5 (CD 3 ) 5 } 2 (m-CH 2 ) 2 ] is denoted by D-Ir 2 ) was synthesized by using the same procedure as that for Ir 2 , but with deuterated trans-[Ir 2 {Z 5 -C 5 (CD 3 ) 5 } 2 (m-Cl) 2 Cl 2 ] as a starting material. 32 The deuterated complex trans-[Ir 2 {Z 5 -C 5 (CD 3 ) 5 } 2 -(m-Cl) 2 Cl 2 ] was synthesized by modifying the procedure for the corresponding Rh analogue. 33 All reagents were purchased from Aldrich, Strem, Wako Chemicals, and Tokyo Kasei Kogyo, and used as received unless otherwise noted.…”