Synthetic and Structural Investigations of Linear and Macrocyclic Nickel/Iron/Sulfur Cluster Complexes

Abstract

Three series of new Ni/Fe/S cluster complexes have been prepared and structurally characterized. One series of such complexes includes the linear type of (diphosphine)Ni-bridged double-butterfly Fe/S complexes [(μ-RS)(μ-S═CS)Fe(2)(CO)(6)](2)[Ni(diphosphine)] (1-6; R = Et, t-Bu, n-Bu, Ph; diphosphine = dppv, dppe, dppb), which were prepared by reactions of monoanions [(μ-RS)(μ-CO)Fe(2)(CO)(6)](-) (generated in situ from Fe(3)(CO)(12), Et(3)N, and RSH) with excess CS(2), followed by treatment of the resulting monoanions [(μ-RS)(μ-S═CS)Fe(2)(CO)(6)](-)with (diphosphine)NiCl(2). The second series consists of the macrocyclic type of (diphosphine)Ni-bridged double-butterfly Fe/S complexes [μ-S(CH(2))(4)S-μ][(μ-S═CS)Fe(2)(CO)(6)](2)[Ni(diphosphine)] (7-9; diphosphine = dppv, dppe, dppb), which were produced by the reaction of dianion [{μ-S(CH(2))(4)S-μ}{(μ-CO)Fe(2)(CO)(6)}(2)](2-) (formed in situ from Fe(3)(CO)(12), Et(3)N, and dithiol HS(CH(2))(4)SH with excess CS(2), followed by treatment of the resulting dianion [{μ-S(CH(2))(4)S-μ}{(μ-S═CS)Fe(2)(CO)(6)}(2)](2-) with (diphosphine)NiCl(2). However, more interestingly, when dithiol HS(CH(2))(4)SH (used for the production of 7-9) was replaced by HS(CH(2))(3)SH (a dithiol with a shorter carbon chain), the sequential reactions afforded another type of macrocyclic Ni/Fe/S complex, namely, the (diphosphine)Ni-bridged quadruple-butterfly Fe/S complexes [{μ-S(CH(2))(3)S-μ}{(μ-S═CS)Fe(2)(CO)(6)}(2)](2)[Ni(diphosphine)](2) (10-12; diphosphine = dppv, dppe, dppb). While a possible pathway for the production of the two types of novel metallomacrocycles 7-12 is suggested, all of the new complexes 1-12 were characterized by elemental analysis and spectroscopy and some of them by X-ray crystallography.

Synthesis, Characterization, and X‐ray Crystal Structures of (Diphosphine)Ni(dmit) and (Diphosphine)Ni(dmio) (Diphosphine = dppv, dppb) Complexes

“…As a continuation of our studies on (diphosphine)NiCl 2 ,20 herein we report the synthesis of four new (diphosphine)Ni(dithiolate) (diphosphine = dppv, dppb) complexes, where dithiolate ligands are 2‐thioxo‐1, 3‐dithiole‐4, 5‐dithiolate (dmit) and 2‐oxo‐1, 3‐dithiole‐4, 5‐dithiolate (dmio). In the end, complexes (dppv)Ni(dmit) ( 1 ), (dppb)Ni(dmit) ( 2 ), (dppv)Ni(dmio) ( 3 ), and (dppb)Ni(dmio) ( 4 ) were prepared in high yields and fully characterized by various spectroscopy, as well as 1 , 3 , and 4 were established by X‐ray crystallography.…”

Synthesis and molecular structures of the 52-electron triiron telluride clusters [Fe3(CO)8(μ3-Te)2(κ2-diphosphine)] - Electrochemical properties and activity as proton reduction catalysts

“…A further development of [FeFe]-hydrogenase biomimics has been to replace the organic dithiolate linking group with a metal fragment (Fig. 1b), with examples containing nickel and platinum being widely studied [35][36][37][38][39][40]. A large number of transition metal chalcogenide complexes of high nuclearity (three or more transition metals) containing phosphine ligands has been synthesised and structurally characterized , but to our knowledge none have been studied as proton reduction catalysts.…”

[NiFe] hydrogenases: how close do structural and functional mimics approach the active site?

“…63 In 73, Ru was replaced with Fe, the aryl ligand with three triethylphosphite {P(OEt) 3 } ligands, and, crucially, sodium methoxide (MeONa) was used as a base instead of water. Complex [73]…”