Tsuyoshi Matsumoto
Research interests
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InterestsBioinorganic Chemistry, Inorganic Biochemistry
Publications
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4.66Impact points
Model Studies of Methyl CoM Reductase: Methane Formation via CH(3)-S Bond Cleavage of Ni(I) Tetraazacyclic Complexes Having Intramolecular Methyl Sulfide Pendants.
Inorganic chemistry. 03/2012;
The Ni(I) tetraazacycles [Ni(dmmtc)](+) and [Ni(mtc)](+), which have methylthioethyl pendants, were synthesized as models of the reduced state of the active site of methyl coenzyme M reductase (MCR), and their structures and redox properties were elucidated (dmmtc, 1,8-dimethyl-4,11-bis{(2-methylthi... [more] The Ni(I) tetraazacycles [Ni(dmmtc)](+) and [Ni(mtc)](+), which have methylthioethyl pendants, were synthesized as models of the reduced state of the active site of methyl coenzyme M reductase (MCR), and their structures and redox properties were elucidated (dmmtc, 1,8-dimethyl-4,11-bis{(2-methylthio)ethyl}-1,4,8,11-tetraaza-1,4,8,11-cyclotetradecane; mtc, 1,8-{bis(2-methylthio)ethyl}-1,4,8,11-tetraaza-1,4,8,11-cyclotetradecane). The intramolecular CH(3)-S bond of the thioether pendant of [Ni(I)(dmmtc)](OTf) was cleaved in THF at 75 °C in the presence of the bulky thiol DmpSH, which acts as a proton source, and methane was formed in 31% yield and a Ni(II) thiolate complex was concomitantly obtained (Dmp = 2,6-dimesityphenyl). The CH(3)-S bond cleavage of [Ni(I)(mtc)](+) also proceeded similarly, but under milder conditions probably due to the lower potential of the [Ni(I)(mtc)](+) complex. These results indicate that the robust CH(3)-S bond can be homolytically cleaved by the Ni(I) center when they are properly arranged, which highlights the significance of the F430 Ni environment in the active site of the MCR protein.
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4.66Impact points
Coordination of methyl coenzyme m and coenzyme m at divalent and trivalent nickel cyclams: model studies of methyl coenzyme m reductase active site.
Inorganic chemistry. 03/2012; 51(6):3690-7.
Divalent and trivalent nickel complexes of 1,4,8,11-tetraazacyclotetradecane, denoted as cyclam hereafter, coordinated by methyl coenzyme M (MeSCoM(-)) and coenzyme M (HSCoM(-)) have been synthesized in the course our model studies of methyl coenzyme M reductase (MCR). The divalent nickel complexes ... [more] Divalent and trivalent nickel complexes of 1,4,8,11-tetraazacyclotetradecane, denoted as cyclam hereafter, coordinated by methyl coenzyme M (MeSCoM(-)) and coenzyme M (HSCoM(-)) have been synthesized in the course our model studies of methyl coenzyme M reductase (MCR). The divalent nickel complexes Ni(cyclam)(RSCoM)(2) (R = Me, H) have two trans-disposed RSCoM(-) ligands at the nickel(II) center as sulfonates, and thus, the nickels have an octahedral coordination. The SCoM(2-) adduct Ni(cyclam)(SCoM) was also synthesized, in which the SCoM(2-) ligand chelates the nickel via the thiolate sulfur and a sulfonate oxygen. The trivalent MeSCoM adduct [Ni(cyclam)(MeSCoM)(2)](OTf) was synthesized by treatment of [Ni(cyclam)(NCCH(3))(2)](OTf)(3) with ((n)Bu(4)N)[MeSCoM]. A similar reaction with ((n)Bu(4)N)[HSCoM] did not afford the corresponding trivalent HSCoM(-) adduct, but rather the divalent nickel complex polymer [-Ni(II)(cyclam)(CoMSSCoM)-](n) was obtained, in which the terminal thiol of HSCoM(-) was oxidized to the disulfide (CoMSSCoM)(2-) by the Ni(III) center.
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5.50Impact points
Dihydrogen activation by sulfido-bridged dinuclear Ru/Ge complexes: insight into the [NiFe] hydrogenase unready state.
Chemical communications (Cambridge, England). 11/2010; 47(3):1030-2.
A S/SH bridged hetero-dinuclear Ru/Ge complex cation reacted with H(2) to afford the μ-S/μ-H complex. The reaction was considerably slower compared to that of the μ-S/μ-OH complex. Thus, the μ-S/μ-SH and μ-S/μ-OH complexes might provide models for the unready and ready states, respectively, of [NiFe... [more] A S/SH bridged hetero-dinuclear Ru/Ge complex cation reacted with H(2) to afford the μ-S/μ-H complex. The reaction was considerably slower compared to that of the μ-S/μ-OH complex. Thus, the μ-S/μ-SH and μ-S/μ-OH complexes might provide models for the unready and ready states, respectively, of [NiFe] hydrogenase.
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11.83Impact points
Dodecanuclear-ellipse and decanuclear-wheel nickel(II) thiolato clusters with efficient femtosecond nonlinear absorption.
Angewandte Chemie (International ed. in English). 06/2010; 49(25):4209-12.
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4.08Impact points
A dinuclear nickel complex modeling of the Ni(d)(II)-Ni(p)(I) state of the active site of acetyl CoA synthase.
Dalton transactions (Cambridge, England : 2003). 03/2010; 39(12):2995-7.
The dinuclear Ni(II)-Ni(I) complex Ni(II)(dadt(Et))Ni(I)(SDmp)(PPh(3)) was synthesized as a Ni(II)(d)-Ni(I)(p) model of the A-cluster in acetyl CoA synthase. This complex was reacted with Co(dmgBF(2))(2)(Me)(Py) and KSDmp successively to afford Ni(dadt(Et))Ni(Me)(SDmp), which further reacts with CO ... [more] The dinuclear Ni(II)-Ni(I) complex Ni(II)(dadt(Et))Ni(I)(SDmp)(PPh(3)) was synthesized as a Ni(II)(d)-Ni(I)(p) model of the A-cluster in acetyl CoA synthase. This complex was reacted with Co(dmgBF(2))(2)(Me)(Py) and KSDmp successively to afford Ni(dadt(Et))Ni(Me)(SDmp), which further reacts with CO to afford the acetylthioester CH(3)C(O)SDmp via reductive elimination.
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34.48Impact points
Host plant genome overcomes the lack of a bacterial gene for symbiotic nitrogen fixation.
Nature. 11/2009; 462(7272):514-7.
Homocitrate is a component of the iron-molybdenum cofactor in nitrogenase, where nitrogen fixation occurs. NifV, which encodes homocitrate synthase (HCS), has been identified from various diazotrophs but is not present in most rhizobial species that perform efficient nitrogen fixation only in symbio... [more] Homocitrate is a component of the iron-molybdenum cofactor in nitrogenase, where nitrogen fixation occurs. NifV, which encodes homocitrate synthase (HCS), has been identified from various diazotrophs but is not present in most rhizobial species that perform efficient nitrogen fixation only in symbiotic association with legumes. Here we show that the FEN1 gene of a model legume, Lotus japonicus, overcomes the lack of NifV in rhizobia for symbiotic nitrogen fixation. A Fix(-) (non-fixing) plant mutant, fen1, forms morphologically normal but ineffective nodules. The causal gene, FEN1, was shown to encode HCS by its ability to complement a HCS-defective mutant of Saccharomyces cerevisiae. Homocitrate was present abundantly in wild-type nodules but was absent from ineffective fen1 nodules. Inoculation with Mesorhizobium loti carrying FEN1 or Azotobacter vinelandii NifV rescued the defect in nitrogen-fixing activity of the fen1 nodules. Exogenous supply of homocitrate also recovered the nitrogen-fixing activity of the fen1 nodules through de novo nitrogenase synthesis in the rhizobial bacteroids. These results indicate that homocitrate derived from the host plant cells is essential for the efficient and continuing synthesis of the nitrogenase system in endosymbionts, and thus provide a molecular basis for the complementary and indispensable partnership between legumes and rhizobia in symbiotic nitrogen fixation.
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4.37Impact points
Evidence for a Rapid Degenerate Hetero-Cope-Type Rearrangement in [Cp*W(S)(2)S-CH(2)-CH==CH(2)].
Chemistry, an Asian journal. 11/2009;
Treatment of the salt [PPh(4)](+)[Cp*W(S)(3)](-) (6) with allyl bromide gave the neutral complex [Cp*W(S)(2)S-CH(2)-CH==CH(2)] (7). The product 7 was characterized by an X-ray crystal structure analysis. Complex 7 features dynamic NMR spectra that indicate a rapid allyl automerization process. From ... [more] Treatment of the salt [PPh(4)](+)[Cp*W(S)(3)](-) (6) with allyl bromide gave the neutral complex [Cp*W(S)(2)S-CH(2)-CH==CH(2)] (7). The product 7 was characterized by an X-ray crystal structure analysis. Complex 7 features dynamic NMR spectra that indicate a rapid allyl automerization process. From the analysis of the temperature-dependent NMR spectra a Gibbs activation energy of DeltaG( not equal) (278 K) approximately 13.7+/-0.1 kcal mol(-1) was obtained [DeltaH( not equal) approximately 10.4+/-0.1 kcal mol(-1); DeltaS( not equal) approximately -11.4 cal mol(-1) K(-1)]. The DFT calculation identified an energetically unfavorable four-membered transition state of the "forbidden" reaction and a favorable six-membered transition state of the "Cope-type" allyl rearrangement process at this transition-metal complex core.
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9.43Impact points
Dinuclear nickel complexes modeling the structure and function of the acetyl CoA synthase active site.
Proceedings of the National Academy of Sciences of the United States of America. 08/2009; 106(29):11862-6.
A dinuclear nickel complex with methyl and thiolate ligands, Ni(dadt(Et))Ni(Me)(SDmp) (2), has been synthesized as a dinuclear Ni(d)-Ni(p)-site model of acetyl-CoA synthase (ACS) (dadt(Et) is N,N'-diethyl-3,7-diazanonane-1,9-dithiolate; Dmp is 2,6-dimesitylphenyl). Complex 2 was prepared via 2 m... [more] A dinuclear nickel complex with methyl and thiolate ligands, Ni(dadt(Et))Ni(Me)(SDmp) (2), has been synthesized as a dinuclear Ni(d)-Ni(p)-site model of acetyl-CoA synthase (ACS) (dadt(Et) is N,N'-diethyl-3,7-diazanonane-1,9-dithiolate; Dmp is 2,6-dimesitylphenyl). Complex 2 was prepared via 2 methods: (i) ligand substitution of a dinuclear Ni(II)-Ni(II) cation complex [Ni(dadt(Et)) Ni(tmtu)2] (OTf)2 (1) with MeMgBr and KSDmp (tmtu is tetramethylthiourea), (ii) methyl transfer from methylcobaloxime Co(dmgBF2)2(Me)(Py) (5) to a Ni(II)-Ni(0) complex such as [Ni(dadt(Et))Ni(cod)] (3), generated in situ from Ni(dadt(Et)) and Ni(cod)(2), followed by addition of KSDmp (cod is 1,5-cyclooctadiene; dmgBF2 is difluoroboryl-dimethylglyoximate). Method ii models the formation of Nip-Me species proposed as a plausible intermediate in ACS catalysis. The reaction of 2 with excess CO affords the acetylthioester CH3C(O)SDmp (8) with concomitant formation of Ni(dadt(Et))Ni(CO)2 (9) and Ni(CO)4 plus Ni(dadt(Et)). When complex 2 is treated with 1 equiv of CO in the presence of excess 1,5-cyclooctadiene, the formation of 9 and Ni(CO)4 is considerably suppressed, and instead the dinuclear Ni(II)-Ni(0) complex is generated in situ, which further affords 2 upon successive treatment with Co(dmgBF2)2(Me)(Py) (5) and KSDmp. These results suggest that (i) ACS catalysis could include the Nid(II)-Nip(0) state as the active species, (ii) The Nid(II)-Nip(0) species could first react with methylcobalamin to afford Nid(II)-Nip(II)-Me, and (iii) CO insertion into the Nip-Me bond and the successive reductive elimination of acetyl-CoA occurs immediately when CoA is coordinated to the Nip site to form the active Nid(II)-Nip(0) species.
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4.66Impact points
Synthesis and reactions of mono- and dinuclear Ni(I) thiolate complexes.
Inorganic chemistry. 04/2009; 48(5):2215-23.
The dinuclear and mononuclear nickel(I) thiolates, [Ni(PPh(3))(mu-SR)](2) (1a: R is 2,4,6-triisopropylphenyl (Tip), 1b: R is 1-adamantyl (Ad)), (DxpS)Ni(mu-SDxp)Ni(PPh(3)) (2) (Dxp is 2,6-dixylylphenyl), and Ni(SDmp)(PPh(3)) (3) (Dmp is 2,6-dimesitylphenyl), have been synthesized by the reaction of ... [more] The dinuclear and mononuclear nickel(I) thiolates, [Ni(PPh(3))(mu-SR)](2) (1a: R is 2,4,6-triisopropylphenyl (Tip), 1b: R is 1-adamantyl (Ad)), (DxpS)Ni(mu-SDxp)Ni(PPh(3)) (2) (Dxp is 2,6-dixylylphenyl), and Ni(SDmp)(PPh(3)) (3) (Dmp is 2,6-dimesitylphenyl), have been synthesized by the reaction of the nickel(I) amide Ni{N(SiMe(3))(2)}(PPh(3))(2) with the corresponding thiols. The two nickel centers of 1a and 1b are equivalent, and are linked by two thiolato sulfurs and a Ni-Ni bond, whereas the two inequivalent nickels of 2 are connected by a SDxp sulfur, a eta(2)/eta(3)-xylyl group of the other SDxp ligand, and a Ni-Ni bond. A slightly bulkier m-terphenyl thiolate, SDmp, prevents its nickel complex from forming a Ni-Ni bond, and the mononuclear nickel(I) center of 3 is bound to PPh(3) and SDmp through interactions with the sulfur and a eta(2)-mesityl. The coordinatively unsaturated nickel(I) complex 3 is reactive, and the reaction of 3 with TEMPO generated diamagnetic Ni(SDmp)(PPh(3))(O,N:eta(2)-TEMPO) (4). N-Heterocyclic carbenes, 1,3,4,5-tetramethylimidazolin-2-ylidene (IMe') and 1,3-bis-(2,4,6-trimethylphenyl)imidazolin-2-ylidene (IMes), also react with 3 to afford a dinuclear nickel(I) complex, [Ni(IMe')(mu-SDmp)](2) (5), and a mononuclear nickel(I) complex, Ni(SDmp)(IMes) (6), respectively. The reaction of 3 with 1 equiv of (t)BuNC afforded the dinuclear complex [Ni(CN(t)Bu)(mu-SDmp)](2) (7), whereas the analogous reaction with 1 equiv of CO resulted in a mixture of Ni(PPh(3))(2)(CO)(2) and Ni(CO)(SDmp)(2)(PPh(3)) (8).
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4.66Impact points
Structural Models for the Active Site of Acetyl-CoA Synthase: Synthesis of Dinuclear Nickel Complexes Having Thiolate, Isocyanide, and Thiourea on the Ni(p) Site.
Inorganic chemistry. 02/2009;
The trinuclear nickel complex [{Ni(dadt(Et))}(2)Ni](NiBr(4)) (dadt(Et) = N,N'-diethyl-3,7-diazanonane-1,9-dithiolate) (1a), prepared by the reaction of Ni(dadt(Et)) and Ni(EtOH)(4)Br(2), was found to serve as a useful synthetic precursor of various dinuclear nickel complexes modeling the active ... [more] The trinuclear nickel complex [{Ni(dadt(Et))}(2)Ni](NiBr(4)) (dadt(Et) = N,N'-diethyl-3,7-diazanonane-1,9-dithiolate) (1a), prepared by the reaction of Ni(dadt(Et)) and Ni(EtOH)(4)Br(2), was found to serve as a useful synthetic precursor of various dinuclear nickel complexes modeling the active site of acetyl-CoA synthase (ACS). The reactions of 1a with 4 equiv of the potassium salts of arenethiolates in ethanol produced a series of dinuclear nickel thiolate complexes Ni(dadt(Et))Ni(SAr)(2) (Ar = Ph (2a), p-Tol (2b), 2,4,6-triisopropylphenyl (Tip) (2c)) in good yields. The analogous reactions of 1a with Ag(OTf) in the presence of (t)BuNC and (NMe(2))(2)CS (tmtu) generated the dicationic dinuclear nickel complexes [Ni(dadt(Et))Ni((t)BuNC)(2)](OTf)(2) (3) and [Ni(dadt(Et))Ni(tmtu)(2)](OTf)(2) (4), respectively. The molecular structures of 1a, 2a-c, 3, and 4 determined by X-ray analysis compare well with that of A-cluster in ACS.
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4.66Impact points
Synthesis of Ge2NiS4 clusters and the thermal transformation to a Ge4Ni6S12 cluster.
Inorganic chemistry. 04/2008; 47(6):1901-3.
The reaction of Ni(dppe)Cl2 and syn-[DmpGe(SLi)(mu-S)2Ge(SLi)Dmp] prepared in situ from syn-[DmpGe(SH)(mu-S)2Ge(SH)Dmp] (1) and n-BuLi (2 equiv) afforded the Ge2NiS4 cluster, [DmpGe(mu-S)]2(mu-S)2Ni(dppe) (2) (Dmp = 2,6-dimesitylphenyl). The nickel in 2 assumes a slightly distorted square planar geo... [more] The reaction of Ni(dppe)Cl2 and syn-[DmpGe(SLi)(mu-S)2Ge(SLi)Dmp] prepared in situ from syn-[DmpGe(SH)(mu-S)2Ge(SH)Dmp] (1) and n-BuLi (2 equiv) afforded the Ge2NiS4 cluster, [DmpGe(mu-S)]2(mu-S)2Ni(dppe) (2) (Dmp = 2,6-dimesitylphenyl). The nickel in 2 assumes a slightly distorted square planar geometry. However, another Ge2NiS4 cluster, [DmpGe(mu-S)]2(mu-S)2Ni(PPh3)2 (3) obtained from a similar reaction with Ni(PPh3)2Cl2, contains the nickel in a tetrahedron. When 3 was heated to 120 degrees C in toluene, a novel Ge4Ni6S12 cluster [DmpGe(mu-S)3]4Ni6 (5) was obtained. In cluster 5, six nickels form an octahedron with the nickels occupying its vertexes, and four DmpGeS3 units cap half of the trigonal faces.
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4.37Impact points
Synthesis of syn-2,4-dimercapto-1,3,2,4-dithiadigermetane and its application to Ge2PdS4 cluster synthesis.
Chemistry, an Asian journal. 04/2008; 3(3):607-13.
The sulfurization of DmpGeH(3) (Dmp=2,6-dimesitylphenyl) afforded the trinuclear germanium sulfide [DmpGe(mu-S)](2)(mu-S)(2)Ge(SH)-Dmp and a series of polythiadigermabicyclo[x.1.1]alkanes (x=3, 4, 5). The reduction of the S--S bonds of these germabicycloalkanes by NaBH(4) at 0 degrees C afforded the... [more] The sulfurization of DmpGeH(3) (Dmp=2,6-dimesitylphenyl) afforded the trinuclear germanium sulfide [DmpGe(mu-S)](2)(mu-S)(2)Ge(SH)-Dmp and a series of polythiadigermabicyclo[x.1.1]alkanes (x=3, 4, 5). The reduction of the S--S bonds of these germabicycloalkanes by NaBH(4) at 0 degrees C afforded the dinuclear mercaptogermane syn-[DmpGe(SH)(mu-S)(2)Ge(SH)-Dmp] (5) in good yield. The reaction of [Pd(dppe)Cl(2)] (dppe=1,2-bis(diphenylphosphanyl)ethane) and the dilithium salt of 5 prepared in situ by the addition of nBuLi (2 equiv) gave the Ge(2)PdS(4) cluster [DmpGe(mu-S)](2)[(mu-S)(2)Pd(dppe)], in which the dithiadigermetanedithiolate is bound to the Pd atom at the two thiolato sulfur atoms. The same reaction with [Pd(PPh(3))(2)Cl(2)] gave another Ge(2)PdS(4) cluster, [DmpGe(mu-S)](2)[(mu-S)(2)Pd(PPh(3))], but with the dithiadigermetanedithiolate and the Pd center conjoined through a mu-S atom between the two germanium atoms in addition to the two thiolato sulfur atoms to form a highly distorted cluster core. The formation of two different types of Ge(2)PdS(4) clusters represents the usefulness of 5 in the synthesis of various polynuclear complexes composed of germanium and transition metals.
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8.58Impact points
A functional hydrogenase model: reversible interconversion of H2 and H2O by a hydroxo/sulfido-bridged dinuclear ruthenium-germanium complex.
Journal of the American Chemical Society. 03/2008; 130(8):2458-9.
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11.83Impact points
Heterolytic dihydrogen activation by a sulfido- and oxo-bridged dinuclear germanium-ruthenium complex.
Angewandte Chemie (International ed. in English). 02/2008; 47(10):1913-5.
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4.66Impact points
Mono{hydrotris(mercaptoimidazolyl)borato} complexes of manganese(II), iron(II), cobalt(II), and nickel(II) halides.
Inorganic chemistry. 12/2006; 45(24):9914-25.
A series of [Tm(Me)M(mu-Cl)]2 and Tm(R)MCl (Tm(R) = tris(mercaptoimidazolyl)borate; R = Me, tBu, Ph, 2,6-iPr2C6H3 (Ar); M = Mn, Fe, Co, Ni) complexes have been prepared by treatment of NaTm(Me) or LiTm(R) with an excess amount of metal(II) chlorides, MCl2. Treatment of Tm(R)MCl (R = tBu, Ph, Ar) wit... [more] A series of [Tm(Me)M(mu-Cl)]2 and Tm(R)MCl (Tm(R) = tris(mercaptoimidazolyl)borate; R = Me, tBu, Ph, 2,6-iPr2C6H3 (Ar); M = Mn, Fe, Co, Ni) complexes have been prepared by treatment of NaTm(Me) or LiTm(R) with an excess amount of metal(II) chlorides, MCl2. Treatment of Tm(R)MCl (R = tBu, Ph, Ar) with NaI led to a halide exchange to afford Tm(R)MI. The molecular structures of [Tm(Me)M(mu-Cl)]2 (M = Mn, Ni), [Tm(Me)Ni(mu-Br)]2, Tm(tBu)MCl (M = Fe, Co), Tm(Ph)MCl (M = Mn, Fe, Co, Ni), Tm(Ar)MCl (M = Mn, Fe, Co, Ni), Tm(Ph)MI (M = Mn, Co), and Tm(Ar)MI (M = Fe, Co, Ni) have been determined by X-ray crystallography. The Tm(R) ligands occupy the tripodal coordination site of the metal ions, giving a square pyramidal or trigonal bipyramidal coordination geometry for Tm(Me)M(mu-Cl)]2 and a tetrahedral geometry for the Tm(R)MCl complexes, where the S-M-S bite angles are larger than the reported N-M-N angles of the corresponding hydrotris(pyrazolyl)borate (Tp(R)) complexes. Treatment of Tm(Ph)2Fe with excess FeCl2 affords Tm(Ph)FeCl, indicating that Tm(R)2M as well as Tm(R)MCl is formed at the initial stage of the reaction between MCl2 and the Tm(R) anion.
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11.83Impact points
Nickel(II) thiolate complexes with a flexible cyclo-{Ni10S20} framework.
Angewandte Chemie (International ed. in English). 07/2006; 45(23):3768-72.
Following (2)
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Yumei Song
Seattle Children's Hospital -
Chi Zhang
Jiangsu University -
Norio Suganuma
Aichi University of Education, Japan
Topics (3)
