“…Complex 23 shows an irreversible oxidation in DMF with E pc = −0.32 V, similar to the behavior of 1 and related complexes at a lower temperature where dimerization of the generated Ni III monoanion is likely 10 Depictions of structurally proven types of μ 2 -S bridging modes ( A − Y ) based on the cis -Ni II S 2 N 2 coordination unit and taken from this work and literature reports (* = this work): * A , B , * C , D , E , , F , * G , * H , * I , * K , − ,− L , * M , * N , * O , P , Q , R , S , *T , , U , *V , W , ,,, X , Y . , Also shown are bridging modes of the CODH/ACS A-clusters (first row). …”
Section: Resultssupporting
confidence: 54%
“…Depictions of structurally proven types of μ 2 -S bridging modes ( A − Y ) based on the cis -Ni II S 2 N 2 coordination unit and taken from this work and literature reports (* = this work): * A , B , * C , D , E , , F , * G , * H , * I , * K , − ,− L , * M , * N , * O , P , Q , R , S , *T , , U , *V , W , ,,, X , Y . , Also shown are bridging modes of the CODH/ACS A-clusters (first row).…”
Sulfur bridging interactions between three cis-planar NiII-S2N2 complexes and NiII, CuI,II, ZnII, and HgII reactants were investigated by synthesis and X-ray crystal structures of some 24 complexes. This work was stimulated by recent crystallographic structures of the A-cluster of carbon monoxide dehydrogenase/acetylcoenzyme A synthase. This bridged biological assembly has the minimal formulation [Fe4S4]-(micro2-SCys)-[M((micro2-SCys)2Gly)Ni] with M = NiII, CuI, and ZnII at sites distal and proximal, respectively, to the iron-sulfur cluster. Bridges supported by representations of the distal nickel site were sought by reactions of the complexes [NiII(LH-S2N2)]2- and [NiII(LR-S2N2)], with 5-5-5 chelate ring patterns. Reaction products implicate the bridges Ni-(micro2-S)1,2-M in a variety of molecular structures, some with previously unknown connectivities of bridge atoms. The most frequently encountered bridge units are the nonplanar rhombs Ni(2-S)2M involving both sulfur atoms of a given complex. Those with M = NiII are biologically relevant inasmuch as the catalytic metal at the proximal site is nickel. The complex [Ni(L-655)]2-, containing the 6-5-5 ring pattern and coordination sphere of the distal nickel site, was prepared and structurally characterized. It was shown to sustain Ni2(micro2-S)2 rhombic interactions in the form of trinuclear [[Ni(L-655)]2Ni]2- and [[Ni(L-655)]Ni(R2PCH2CH2PR2)] (R = Et, Ph) in which the second NiII simulates the proximal site. Bridging interactions of NiII-S2N2 complexes are summarized, and geometrical features of Ni2(2-S)2 rhombs in these complexes, as dependent on ring patterns, are considered (LH-S2N2 = N,N'-ethylenebis(2-mercaptoisobutyramide)(4-); LR-S2N2 = trans-rac-N,N'-bis(2-mercapto-2-methylprop-1-yl)-1,2-cyclohexanediamine(2-); L-655 = N-(2-mercaptopropyl)-N'-(2'-mercaptoethyl)glycinamide(4-)).
“…Complex 23 shows an irreversible oxidation in DMF with E pc = −0.32 V, similar to the behavior of 1 and related complexes at a lower temperature where dimerization of the generated Ni III monoanion is likely 10 Depictions of structurally proven types of μ 2 -S bridging modes ( A − Y ) based on the cis -Ni II S 2 N 2 coordination unit and taken from this work and literature reports (* = this work): * A , B , * C , D , E , , F , * G , * H , * I , * K , − ,− L , * M , * N , * O , P , Q , R , S , *T , , U , *V , W , ,,, X , Y . , Also shown are bridging modes of the CODH/ACS A-clusters (first row). …”
Section: Resultssupporting
confidence: 54%
“…Depictions of structurally proven types of μ 2 -S bridging modes ( A − Y ) based on the cis -Ni II S 2 N 2 coordination unit and taken from this work and literature reports (* = this work): * A , B , * C , D , E , , F , * G , * H , * I , * K , − ,− L , * M , * N , * O , P , Q , R , S , *T , , U , *V , W , ,,, X , Y . , Also shown are bridging modes of the CODH/ACS A-clusters (first row).…”
Sulfur bridging interactions between three cis-planar NiII-S2N2 complexes and NiII, CuI,II, ZnII, and HgII reactants were investigated by synthesis and X-ray crystal structures of some 24 complexes. This work was stimulated by recent crystallographic structures of the A-cluster of carbon monoxide dehydrogenase/acetylcoenzyme A synthase. This bridged biological assembly has the minimal formulation [Fe4S4]-(micro2-SCys)-[M((micro2-SCys)2Gly)Ni] with M = NiII, CuI, and ZnII at sites distal and proximal, respectively, to the iron-sulfur cluster. Bridges supported by representations of the distal nickel site were sought by reactions of the complexes [NiII(LH-S2N2)]2- and [NiII(LR-S2N2)], with 5-5-5 chelate ring patterns. Reaction products implicate the bridges Ni-(micro2-S)1,2-M in a variety of molecular structures, some with previously unknown connectivities of bridge atoms. The most frequently encountered bridge units are the nonplanar rhombs Ni(2-S)2M involving both sulfur atoms of a given complex. Those with M = NiII are biologically relevant inasmuch as the catalytic metal at the proximal site is nickel. The complex [Ni(L-655)]2-, containing the 6-5-5 ring pattern and coordination sphere of the distal nickel site, was prepared and structurally characterized. It was shown to sustain Ni2(micro2-S)2 rhombic interactions in the form of trinuclear [[Ni(L-655)]2Ni]2- and [[Ni(L-655)]Ni(R2PCH2CH2PR2)] (R = Et, Ph) in which the second NiII simulates the proximal site. Bridging interactions of NiII-S2N2 complexes are summarized, and geometrical features of Ni2(2-S)2 rhombs in these complexes, as dependent on ring patterns, are considered (LH-S2N2 = N,N'-ethylenebis(2-mercaptoisobutyramide)(4-); LR-S2N2 = trans-rac-N,N'-bis(2-mercapto-2-methylprop-1-yl)-1,2-cyclohexanediamine(2-); L-655 = N-(2-mercaptopropyl)-N'-(2'-mercaptoethyl)glycinamide(4-)).
“…The resulting Cu 5 S 4 N 4 Cl 3 core contains alternating copper and sulfur atoms with the connectivity of the carbon atoms in bicyclo[3.3.1]nonane (Figure a). M 5 S 4 N 4 X 3 connectivity has been observed in [Ni(II)( 1 )] 2 [Cu(I)I] 3 22 and 15 , each of which contain M(II)N 2 (amine)S 2 (thiolate) [M(II) = Ni(II), Cu(II) 8 ] units bridged by Cu(I)X (X = I, Cl 8 ) groups. 2 (a) Sketch of the Cu 5 S 4 N 4 Cl 3 core in rac- 6 .…”
A series of Cu(II) and Cu(I)/Cu(II) complexes containing the cis-N(amine)(2)S(thiolate)(2) copper complex rac-2 has been synthesized to provide a basis for understanding the charge-transfer spectra of mixed-valence thiolate-bridged Cu(I)/Cu(II) complexes. In combination with Cu(Me(2)-13-N(4)ane), rac-2 yields a monobridged dinuclear homovalent adduct, rac-5, while reaction with CuCl yields the mixed-valance pentanuclear complex rac-6. In the presence of Cu(II)(acac)(2), chiral R,R-1 reacts to form a mixed-valence pentanuclear cation R,R-7. rac-6 exhibits a relatively short Cu(I). Cu(II) contact [2.8231(9) A] and associated structural features that suggest the presence of a weak Cu(I).Cu(II) interaction in a valence-trapped system. Additional structural features in rac-6 and R,R-7 include singly and doubly bridging thiolates, three- and four-coordinated Cu(I) ions, and varying Cu(I) ligand sets. These features extend the types and complexities of electronic absorptions significantly. Spectra of rac-6 and R,R-7 exhibit multiple overlapping absorptions over the entire visible and ultraviolet spectral regions studied, consonant with these observations. Trends resulting from variations in structure type and oxidation state permit a first approach toward developing a detailed assignment of the individual ligand Rydberg, LF, LMCT, MLCT, and possible MMCT absorptions in these complexes.
“…Complexes 223 and 224 utilize complex 8 as the NiN 2 S 2 metalloligand, , and 225 uses the same N 2 S 2 binding site but for Cu 2+ . Both contain three bridging Cu I X units, yielding the incomplete adamantane core.…”
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
