82247-34-5

Upstream product

• 106-54-7 p-Chlorothiophenol 

Downstream Products

• 80764-37-0 (Et₄N)3[MoFe₃S₄(S-p-C₆H₄Cl)3((C₃H₅)2cat)(OPh)] 
• 89345-87-9 (Et₄N)4[Mo₂Fe₆S₈(S-p-C₆H₄Cl)6(catecholato)2] 
• 80702-99-4 3(C₂H₅)4N⁽¹⁺⁾*{MoFe₃S₄(SC₆H₄Cl)4(C₆H₂O₂(CH₂CHCH₂)2)}^(3-)=((C₂H₅)4N)3{MoFe₃S₄(SC₆H₄Cl)4(C₆H₂O₂(CH₂CHCH₂)2)} 

Relevant academic research and scientific papers

Molybdenum Atom Ligand Substitution Reactions of MoFe3S4 Cubane-Type Clusters: Synthesis and Structures of Clusters Containing Mo-Bound Pseudosubstrates of Nitrogenase

The ligand substitution chemistry of the title clusters, containing a Mo atom in a coordination environment similar (by EXAFS criteria) to that in nitrogenase, has been further developed.Reaction of 3- with tetrachlorocatechol (Cl4catH4) yields the doubly bridged double cubane 4- (1).This and analogous clusters form the solvated, spin-quartet, single cubanes *)(MeCN)>2- (2) in acetonitrile solution.These species undergo a number of Fe and Mo site-specific ligand substitution reactions, which are summarized and include catecholate exchange at the Mo site.Reaction of 2 (R=p-C6H4Cl; cat*=3,6-diallylcatecholate) with excess Cl4catH2 and catechol (catH2) yields *)2>4- (cat*=Cl4cat, cat (3)). (Et4N)4 (3) crystallizes in monoclinic space group P21/n with a=18.25(2) Angstroem, b=22.08(3) Angstroem, c=26.21(3) Angstroem, β=99.43(10) deg, and Z=4.The anion consists of two MoFe3S4(S-p-C6H4Cl)2(cat) subclusters joined by two Mo-S(R)-Fe bridges whose elongated bonds contribute to the ready cleavage to 2 in acetonitrile.The ligand binding reactions of 2 and its W analogue were investigated by 1H NMR spectroscopy.In ca.10 mM solutions reactions of 1 equiv of the nitrogenase-related ligands L=CN-, N3-, N2H4, NH3, PhNHNH2, and piperidine were found to be nearly quantitative at 298 K.Spectra at 240 K unambiguously demonstrated binding from the appearance of inequivalent R-substituent resonances in a 2:1 intensity ratio, consistent with *)L>2-,3- clusters (4, M=Mo, W) of Cs symmetry.By variation of R and cat* groups using substitution reactions, diffraction quality crystals of 4 with L=CN- and N3- were obtained. (Et4N)3 crystallizes in orthorhombic space group Pnma with a=22.793(5) Angstroem, b=19.274(3) Angstroem, c=12.456(2) Angstroem, and Z=4. (Et4N)3 crystallizes in space group P21/n with a=19.158(9) Angstroem, b=18.56(1) Angstroem, c=20.15(1) Angstroem, β=105.96(5) deg, and Z=4.The Mo-L portions of these single cubanes are linear (L=CN-) or bent (L=N3-, Mo-N-N=125(1) deg), and Mo-C (2.19(3) Angstroem) and Mo-N (2.17(2) Angstroem) bond distances are consisitent with an intermediate oxidation state (III, IV) of the Mo atom.The results of this and prior investigations have defined means for systematic and specific manipulation of all noncore ligands in 3+ single cubanes, results that should be pertinent to the development of substrate-reducing systems based on reduced (2+) single-cubane clusters.

Doubly Bridged Double Cubanes Containing MFe3S4 Clusters (M = Mo, W). Synthesis, Structure, and Conversion to Spin-Quartet Single Clusters in Solution

Reaction of the Fe(III)-bridged double-cubane clusters 3- with the 3,6-disubstituted catechols R'2catH2 in acetonitrile solution at ambient temperature results in bridge cleavage and formation of the new set of clusters 4- (M = Mo, W; R' = n-Pr, CH2CH=CH2), which are isolated in good yields as Et4N+ salts.The structure of the monoclinic form of (Et4N)4 is reported.It crystallizes in space group C2/c with a = 31.474 (7) Angstroem, b = 19.544 (5) Angstroem, c = 25.182 (6) Angstroem, β = 141.77 (1) grad, and Z = 4; the structure was refined to R = 4.8percent by using 4227 unique data (Fo2 > 3?(Fo2)).The structure of the centrosymmetric anion is that of a doubly bridged double-cubane cluster.Two MoFe3S4(SEt)2(R'2cat) subclusters, of unexpectional dimensions and containing a Mo-R'2cat chelate ring, are joined by two Mo(μ-SEt)Fe bridges.Bridge bond distances are 0.04 - 0.09 Angstroem longer than comparable terminal distances.In solution the clusters undergo complete thiolate ligand substitution with arylthiols RSH affording 4- (R = Ph, p-tolyl, p-C6H4Cl), several of which have been isolated as Et4N+ salts.In coordinating solvents such as Me2SO, acetonitrile, and DMF at ambient temperature the double cubanes are cleaved to the single cluster solvates 2-.On the basis of 1H NMR evidence, all thiolate ligands are present as terminal Fe-SR groups; M atom coordination is completed by a solvent molecule, which is in rapid exchange with bulk solvent.Magnetic susceptibility and EPR spectral properties confirm a S = 3/2 ground state.EPR parameters resemble those of the S = 3/2 spin system of FeMo proteins and the FeMo cofactor of nitrogenase, suggesting an electronic similarity.Solvate clusters undergo a single one-electron reduction at ca. -1.1 to -1.5 V (vs.SCE).This property together with the lability of coordinated solvent molecules leads to the possibility that (reducible) nitrogenase substrates may be bound and activated at the M atom site.