Disulfides complex

In this work we examine the low energy UV-visible absorption spectrum of the [Fe2 ft - S2) P o- 61148) )2] complex, Figure 1, whose synthesis, structure, and properties have recently been reported. The complex contains a [Fe — S — S - Fe] core and is a structural isomer of the 2-Fe [Fe — ill — 8)2 — Fe ferredoxin. The electronic structure of the disulfide complex is, however, unknown, and can be associated with either an antifer-romagnetically (AF) coupled [Fe d ) - - Fe d )] system, or with a... 

In dithiocarbamato complexes such an ambiguity can only occur when at least two dithiocarbamato ligands are bonded to a metal. In that case the question arises whether the compound is a bis (dithiocarbamato) or a thiuram disulfide complex. In these two types of complexes the oxidation number of the metal differs 2 units. 

Excessive halogenation of several dithiocarbamato and thiuram disulfide complexes yields compounds in which the ligand is oxidised to the dipositive 3,5-Ris (N,N dialkyl/minium) frifhio-... 

Oxidation of these complexes with halogen results in the oxidation of the ligand, yielding a thiuram disulfide complex X2M(R4tds), leaving the oxidation state of the metal unchanged (99,100,161). 

Xu et al. [5] described the effect of (z>)-penicillamine on the binding of several antiacetylcholine receptor monoclonal antibodies to the Torpedo acetylcholine receptor. Penicillamine is covalently incorporated into the acetylcholine receptor through SS exchange at the cysteine residues of the a-subunit, altering the antigenic structure of the receptor. This effect on the structure of the native receptor at the neuromuscular junction may be responsible for the establishment of the autoimmune response to the acetylcholine receptor in (i))-penicillamine-induced myasthenia gravis. Cysteine and penicillamine interact to form penicillamine-cysteine mixed disulfide complexes [6] ... 

Tp " JMgMe, 42 316 [Tp JZnOH complexes, 42 354-359 use in radiocarbon measurement, 3 303 Carbon disulfide complexes, osmium, 37 239 insertion reactions... 

Figure 12 Structure of the bis(vinyl disulfide) complex [MojO C CC Me) , 2 133...

Figure 9-39. Sometimes the oxidation of thiolate complexes results in the formation of disulfide complexes rather than oxygen transfer products.

Carbon disulfide complexes are included for comparison. The C=C bond length of free molecules ranges from 1.309 to 1.312 A. b Perpendicular refers to the molecular structure containing a coordinated double bond perpendicular to the molecular plane, and in-plane to that containing the double bond lying in the molecular plane. 

Figure 5.50 Molecular structures of the disulfide-linked ruthenium polypyridyl methylviologen diads, [RuC VC6S]2, and ruthenium disulfide complexes, [RuCmS]2 (of variable chain lengths n and m, respectively), plus the structure of the electron acceptor 4ZV, reported by Yamada and co-workers [81]...

Figure 10. Hypothetical mechanisms for the oxidative chemistry ofl and the reaction of the one-electron oxidation product, l+m. Left from l+% The process corresponding to the slow loss of the EPR signal and two paths for the formation of disulfides upon a second one-electron oxidation. Path A Retaining a dimeric structure, the two-electron reduction of the disulfide regenerates 1. Path B The second one-electron oxidation cleaves the dimer leading to the formation of a mononuclear disulfide complex, in analogy with that shown in Figure 5 and a mononuclear Ni(II) complex that rapidly dimerizes to form 2, in analogy with chemistry known for similar complexes (85). Reduction of the disulfide leads to production of the same mononuclear Ni(II) complex.

Table 6 Structures Cobalt-Carbon Disulfide Complexes ...

The manganese carbonyl disulfide complex (12) inserts various metal fragments into the S-S bond (Scheme 8). On the other hand, Me2S inserts into the Mn-Mn bond and tertiary phosphines substitute CO ligands. Heterobimetallic disulfides and diselenides analogous to (12) have been... 

Thiirane 149 and 2-methylthiirane 150 react with rhenium complex 151 (Cp ReCU Cp = EtMe4Cs), at room temperature in THE solution, to form disulfide complex 152 (Scheme 29) <20000M4925>. 

Ionization constants of 2-carboxypiperazine and the three dicarboxylic acids have been determined (1684), and the nucleophilic reactivity of piperazine compared to other amines in reactions with l-chloro-2,4-dinitrobenzene has been measured (1685). The rate of quaternization of l-ethoxycarbonyl-4-methylpiperazine with allyl bromide (/ = 2.25 1/mol min) and methyl iodide (10A = 1.22) have been measured in acetone-water solution (1686). The composition and structure of the 2-methylpiperazine-carbon disulfide complex has been investigated it was a mixture of l-dithiocarboxy-3-methylpiperazine (138) and the 2-methylpiperazine salt of l,4-bis(dithiocarboxy)-2-methylpiperazine (1687). 

Berges J., Kassab E., Conte D., Adjadj E., Houee-Levin C, Ab initio calculations on arginine-disulfide complexes modelling the one-electron reduction of lysozyme. Comparison to an experimental reinvestigation, J. Phys. Chem., 1997,101,7809-7817. 

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