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Jing-Lin Zuo

Publications and source records attributed to Jing-Lin Zuo.

15 recordsLinked to original sources
PubMed2006

Structural and magnetic studies on cyano-bridged rectangular Fe2M2 (M = Cu, Ni) clusters.

Using the tricyano precursor, (Bu4N)[(Tp)Fe(CN)3] (Tp = Tris(pyrazolyl) hydroborate) (1), four new tetranuclear clusters, [(Tp)Fe(CN)3Cu(Tp)]2.2H2O (2), [(Tp)Fe(CN)3Cu(bpca)]2.4H2O (3) (bpca = bis(2-pyridylcarbonyl)amidate anion), [(Tp)Fe(CN)3Ni(tren)]2(ClO4)2.2H2O (4) (tren = tris(2-amino)ethylamine), and [(Tp)Fe(CN)3Ni(bipy)2]2[(Tp)Fe(CN)3]2.6H2O (5) (bipy = 2,2'-bipyridine), have been synthesized and structurally characterized. The four clusters possess similar square structures, where FeIII and MII (M = CuII or NiII) ions alternate at the rectangle corners. There exist intermolecular - stacking interactions through pyrazolyl groups of Tp- ligands in complexes 2 and 4, which lead to 1D chain structures. Complex 5 shows a 3D network structure through the coexistence of - stacking effects and hydrogen-bonding interactions. Magnetic studies show intramolecular ferromagnetic interactions in all four clusters. The exchange parameters are +11.91 and +1.38 cm(-1) for clusters 2 and 3, respectively, while uniaxial molecular anisotropy can be detected in complex 3 due to the distorted core in its molecular structure. Complex 4 has a ground state of S = 3 and shows SMM behavior with an effective energy barrier of U = 18.9 cm(-1). Unusual spin-glass-like dynamic relaxations are observed for complex 5.

Journal Article↗
PubMed2006

Cyano-bridged pentanuclear Fe(III)3M(II)2 (M = Ni, Co, Fe) clusters: synthesis, structures, and magnetic properties.

The reactions of [M(II)(Tpm(Me))(H2O)3]2+ (M = Ni, Co, Fe; Tpm(Me) = tris(3,5-dimethyl-1-pyrazoyl)methane) with [Bu4N][(Tp)Fe(III)(CN)3] (Bu4N+ = tetrabutylammonium cation; Tp = tris(pyrazolyl)hydroborate) in MeCN-Et2O afford three pentanuclear cyano-bridged clusters, [(Tp)3(Tpm(Me))2Fe(III)3M(II)2(CN)9]ClO4.15H2O (M = Ni, 1; M = Co, 2) and [(Tp)3(Tpm(Me))2Fe(III)3Fe(II)2(CN)9]BF4.15H2O (3). Single-crystal X-ray analyses reveal that they show the same trigonal bipyramidal structure featuring a D3h-symmetry core, in which two opposing Tpm(Me)-ligated M(II) ions situated in the two apical positions are linked through cyanide bridges to an equatorial triangle of three Tp-ligated Fe(III) (S = 1/2) centers. Magnetic studies for complex 1 show ferromagnetic coupling giving an S = 7/2 ground state and an appreciable magnetic anisotropy with a negative D(7/2) value equal to -0.79 cm(-1). Complex 2 shows zero-field splitting parameters deducted from the magnetization data with D = -1.33 cm(-1) and g = 2.81. Antiferromagnetic interaction was observed in complex 3.

Journal Article↗
PubMed2006

Synthesis, crystal structures, and magnetic properties of cyano-bridged heterobimetallic chains based on [(Tp)Fe(CN)3]-.

With the use of the tailored cyanometalate precursor, (Bu4N)[(Tp)Fe(CN)3] (Tp = Tris(pyrazolyl)hydroborate) as the building block to react with fully solvated Cu(II), Co(II), and Ni(II) cations, four one-dimensional (1D) heterobimetallic cyano-bridged chain complexes of squares, [(Tp)2Fe(III)2(CN)6Cu(CH3OH).2CH3OH]n (1), [(Tp)2Fe(III)2(CN)6Cu(DMF).DMF]n (2), [(Tp)2Fe(III)2(CN)6M(CH3OH)2.2CH3OH]n (M = Co (3) and Ni (4)), have been prepared. In complexes 1 and 2, the Cu(II) ions are pentacoordinated in the form of a slightly distorted square-based pyramid, and they are linked by distorted octahedrons of [(Tp)Fe(CN)3]- to form 1D chains of squares. In complexes 3 and 4, both the central Co(II) and Ni(II) ions have a slightly distorted octahedral coordination geometry, and they are bridged by [(Tp)Fe(CN)3]- to form similar 1D chains of squares. There are weak interchain pi-pi stacking interactions through the pyrazolyl groups of the Tp ligands for complexes 3 and 4. The crystal structures and magnetic studies demonstrate that complexes 1 and 2 exhibit intrachain ferromagnetic coupling and single-chain magnets behavior, and the blocking temperature is ca. 6 K for complex 1 and ca. 3 K for complex 2. Complexes 3 and 4 show significant metamagnetic behavior, where the cyanides mediate the intrachain ferromagnetic coupling between Fe(III) and Co(II) or Ni(II) ions and the interchain pi-pi stacking interactions lead to antiferromagnetic couplings. The field dependence of the magnetization measurements shows that the critical field is around 1 kOe for complex 3 and 0.8 kOe for complex 4 at 1.8 K.

Journal Article↗
PubMed2006

Chiral molecule-based ferrimagnets with helical structures.

Two enantiopure one-dimensional complexes with helical structures, [Mn(3)((R,R)-Salcy)(3)(H2O)(2)Fe(CN)(6).2H2O]n (1) and [Mn(3)((S,S)-Salcy)(3)(H2O)(2)Fe(CN)(6).2H2O]n (2) [Salcy = N,N'-(1,2-cyclohexanediylethylene)bis(salicylideneiminato) dianion], have been synthesized and characterized. Magnetic studies show that both complexes are ferrimagnets with the magnetic transition temperature at 3 K.

Crystallography, X-Ray↗
PubMed2006

Symmetry-based magnetic anisotropy in the trigonal bipyramidal cluster [Tp2(Me3tacn)3Cu3Fe2(CN)6]4+.

Reaction of [(Me3tacn)Cu(H2O)2]2+ (Me3tacn = N,N',N' '-trimethyl-1,4,7-triazacyclononane) with [TpFe(CN)3]- (Tp- = hydrotris(pyrazolyl)borate) in a mixture of ethanol and acetonitrile affords the pentanuclear cluster [Tp2(Me3tacn)3Cu3Fe2(CN)6]4+. Single-crystal X-ray analysis reveals a trigonal bipyramidal structure featuring a D3h-symmetry core in which two opposing FeIII (S = 1/2) centers are linked through cyanide bridges to an equatorial triangle of three CuII (S = 1/2) centers. Fits to variable-temperature dc magnetic susceptibility data are consistent with ferromagnetic coupling to give an S = 5/2 ground state, while fits to low-temperature magnetization data indicate the presence of a large axial zero-field splitting (D = -5.7 cm-1). Frequency dependence observed in the ac magnetic susceptibility data confirms single-molecule magnet behavior, with an effective spin reversal barrier of Ueff = 16 cm-1. When compared with the much lower anisotropy barrier previously observed for the face-centered cubic cluster [Tp8(H2O)6Cu6Fe8(CN)6]4+, the results demonstrate the enormous influence of the geometry in which a given set of metal ions are arranged.

Journal Article↗
PubMed2006

Construction of open metal-organic frameworks based on predesigned carboxylate isomers: from achiral to chiral nets.

The four-connected carboxylate ligand N,N,N',N'-tetrakis(4-carboxyphenyl)-1,4-phenylenediamine (TCPPDA) exists as three stereoisomers: a pair of enantiomers (deltaD2- and lambdaD2-TCPPDA) and a diastereomer (C2h-TCPPDA). TCPPDA was predesigned for the construction of isomeric coordination networks. Reactions of M(NO3)2 (M=Cu, Zn, Co) or Nd(NO)3 with TCPPDA under solvothermal conditions gave rise to five novel porous metal-organic frameworks: [Cu2(D2-tcppda)(H2O)2].2 DMSO.6H2O (1), [Cu2(C2h-tcppda)(H2O)2].2DMSO.6H2O (2), [Co3(D2-Htcppda)2].4DEF.5H2O (3), [Nd2(D2-tcppda)(C2h-tcppda)0.5(DMSO)3]3 DMSO5 H2O (4), and [Zn4O(D2-tcppda)1.5].DMF.H2O (5) (DMSO=dimethyl sulfoxide, DEF=diethylformamide, DMF=dimethylformamide). Complexes 1 and 2 are supramolecular isomers, in which all the ligands adopt pseudotetrahedral (both deltaD2- and lambdaD2-TCPPDA) and rectangular (C2h-TCPPDA) geometries, respectively. Both compounds connect paddlewheel secondary building units (SBUs) to form three-dimensional porous networks possessing PtS and NbO nets, respectively. In 3, all ligands possess pseudotetrahedral (both deltaD2- and lambdaD2-TCPPDA) geometry and link hourglass SBUs to form a three-dimensional porous framework. Compound 4 contains all three stereoisomers (C2-, deltaD2-, and lambdaD2-TCPPDA), thus, has both pseudotetrahedral and rectangular geometries. D2-TCPPDA connects the binuclear neodymium units to generate a two-dimensional layer, further linked by C2h-TCPPDA to create a three-dimensional open framework. In 5, all the ligands possess pseudotetrahedral geometry (D2-TCPPDA), as found in 1 and 3. However, all the TCPPDA ligands in 5 appear as either the deltaD2 or the lambdaD2 form, thus, the whole structure is homochiral. Complex 5 crystallizes in the I4(1)32 space group and the octahedral SBU in 5 is connected by the enantiopure TCPPDA to generate a three-dimensional porous network possessing the corundum Al2O3 net. Complexes 1, 2, and 5 possess permanent porosity, and 4 and 5 exhibit strong luminescence at lambdamax=423 and 424 nm, respectively, upon excitation at 268.5 nm.

Journal Article↗
PubMed2006

Di-mu-acetato-bis[(2-acetylpyridine thiosemicarbazonato)zinc(II)].

The title compound, [Zn2(C2H3O2)2(C8H9N4S)2], is a centrosymmetric dinuclear molecule with two acetate bridging ligands in a syn-syn arrangement. The Zn(II) atom is five-coordinated in a trigonal-bipyramidal configuration by three thiosemicarbazone atoms (two N and one S) and by an O atom from each of the two acetate groups.

Acetates↗
PubMed2006

Syntheses, structures, and magnetic properties of cyano-bridged heterobimetallic complexes based on [Fe(bpca)(CN)3]-.

Two new cyano-bridged one-dimensional heterobimetallic coordination polymers, [(bpca)(2)Fe(III)(2)(CN)(6)Cu(H(2)O)(2).1.5H(2)O](n)() (2) and [(bpca)Fe(III)(CN)(3)Cu(bpca)(H(2)O).H(2)O](n)() (3), and a trinuclear complex, [(bpca)(2)Fe(III)(2)(CN)(6)Mn(CH(3)OH)(2)(H(2)O)(2)].2H(2)O (4), have been synthesized using the tailored tricyanometalate precursor (Bu(4)N)[Fe(bpca)(CN)(3)].H(2)O (1) (Bu(4)N(+) = tetrabutylammonium cation; bpca = bis(2-pyridylcarbonyl)amidate anion) as a building block and structurally characterized. In complex 2, the Cu(II) ions are six-coordinated in an elongated distorted octahedral environment, and they are linked by distorted octahedrons of [Fe(bpca)(CN)(3)](-) to form 1D chain of squares. Complex 3 is an unexpected chiral heterobimetallic helical chain complex, in which the helical chain consists of the asymmetric unit of [(bpca)Fe(CN)(3)Cu(bpca)(H(2)O)]. In complex 4, there are two independent trinuclear clusters in one asymmetric unit, and the coordination modes of the two methanol and two water molecules coordinating to the central Mn(II) ion are different (cis and trans). Complex 2 shows metamagnetic behavior with a Neel temperature of T(N) = 2.2 K and a critical field of 250 Oe at 1.8 K, where the cyanides mediate the intrachain ferromagnetic coupling between the Cu(II) and Fe(III) ions. Complex 3 shows ferromagnetic coupling between Cu(II) and Fe(III) ions, the best-fit for chi(M)T versus T using a 1D alternating chain model leads to the parameters J(1) = 7.9(3) cm(-)(1), J(2) = 1.03(2) cm(-)(1), and g = 2.196(3). Complex 4 exhibits ferrimagnetic behavior caused by the noncompensation of the local interacting spins (S(Mn) = 5/2 and S(Fe) = 1/2) which interact antiferromagnetically through bridging cyano groups.

Journal Article↗
PubMed2005

One-dimensional azido-bridged chiral metal complexes with ferromagnetic or antiferromagnetic interactions: syntheses, structures, and magnetic studies.

One-dimensional chiral copper(II) and manganese(II) coordination polymers with single asymmetric end-to-end (EE) azide bridges, [Cu(R-L)2(N3)]n(ClO4)n (1), [Cu(S-L)2 (N3)]n(ClO4)n (2), [Mn(R-L)2(N3)]n(ClO4)n (3), and [Mn(S-L)2(N3)]n(ClO4)n (4) (R-L or S-L = R- or S-pyridine-2-carbaldehyde-imine), have been synthesized, using azide ions as bridging groups and chiral Schiff bases as auxiliary ligands, and characterized. The crystal structure determination of complexes 1 and 2 reveals the formation of one-dimensional chiral chains, in which the central Cu(II) ion is six-coordinate in the form of an elongated octahedron. Complex 3 consists of chiral helical polymeric chains, in which the central Mn(II) has a slightly distorted octahedral geometry. They all crystallize in the chiral space group P2(1). Complexes 1 and 2 are rare examples that exhibit ferromagnetic interaction between copper(II) ions through the single end-to-end azido bridge. Fitting the susceptibility data for 1 using a 1D uniform chain model led to the parameters J = 0.70(3) cm(-1), g = 2.06(2), and zj' = 0.07(2) cm(-1). The magnetic studies on 3 and 4 show that there is weak antiferromagnetic coupling between the manganese(II) ions.

Journal Article↗
PubMed2004

The observation of superparamagnetic behavior in molecular nanowires.

Using the anionic precursor [(Tp)Fe(CN)3]-, a new one-dimensional Ising cyanide-bridged chain, [(Tp)2FeIII2(CN)6Cu(CH3OH).2CH3OH]n, has been prepared. The crystal structure and magnetic studies demonstrate that it is a single-chain magnet and the blocking temperature is ca. 6 K.

Journal Article↗
PubMed2004

Tris[bis[hydrotris(1-pyrazolyl)borato-kappa3N2,N2',N2"]iron(III)] hexaisothiocyanatoiron(III).

The title compound, [Fe(C(9)H(10)BN(6))(2)](3)[Fe(NCS)(6)] or [Fe(III)(Tp)(2)](3)[Fe(III)(NCS)(6)] [Tp is hydrotris(1-pyrazolyl)borate], crystallizes in space group R-3; the asymmetric unit comprises one-half of an [Fe(Tp)(2)](+) cation, with its Fe atom on a crystallographic inversion centre, and one-sixth of an [Fe(NCS)(6)](3-) anion, on a site of -3 symmetry. The anions and cations are stacked into a three-dimensional supramolecular aggregate via two distinct types of weak C-H.pi interactions.

Journal Article↗
PubMed2003

Vanadium-iron-sulfur clusters containing the cubane-type [VFe3S4] core unit: synthesis of a cluster with the topology of the PN cluster of nitrogenase.

A synthetic method affording a topological analogue of the electron-transfer P-cluster of nitrogenase (Fe(8)S(7)(mu(2)-S(Cys))(2)) in the P(N) state has been devised, based in part on our previous development of cubane-type VFe(3)S(4) clusters (Hauser, C.; Bill, E.; Holm, R. H. Inorg. Chem. 2002, 41, 1615-1624). The cluster [(Tp)VFe(3)S(4)Cl(3)](2-) (1) is converted to [(Tp)VFe(3)S(4)(PR(3))(3)](1+) (R = Et (2), Bu (3)) by reaction with R(3)P. The phosphine ligands are readily substituted, leading to [(Tp)VFe(3)S(4)(SR)(3)](2-) (R = Ph (4), H (5)). Reduction of 2 or 3 with cobaltocene produces the edge-bridged double cubanes [(Tp)(2)V(2)Fe(6)S(8)(PR(3))(4)] (R = Et (6), Bu (7)), which are readily converted to [(Tp)(2)V(2)Fe(6)S(8)(SPh)(4)](4-) (8). The structures of clusters 3-5 and 8 were proven crystallographically. Cluster 8 has the double-cubane structure previously shown for 6, in which two cubane units are bridged by two Fe-(mu(4)-S) bonds. (57)Fe isomer shifts are consistent with the formulation [VFe(2.33+)(3)S(4)](2+) for the single cubanes and the all-ferrous description 2[VFe(2+)(3)S(4)](1+) for the double cubanes. Reaction of 6 with 4 equiv of (Et(4)N)(HS) in acetonitrile results in the insertion of sulfide with concomitant structural rearrangement and the formation of [(Tp)(2)V(2)Fe(6)S(9)(SH)(2)](4-) (10), obtained in ca. 50% yield as the Et(4)N(+) salt. The cluster has C(2) symmetry, with two all-ferrous VFe(3)S(4) fragments bridged by a common mu(6)-S atom and two mu(2)-S atoms that simulate the bridging atoms in the two Fe-(mu(2)-S(Cys))-Fe bridges of the P(N) cluster. The bridge pattern V(2)Fe(6)(mu(2)-S)(2)(mu(3)-S)(6)(mu(6)-S) and cluster shape match those of the native cluster. A best-fit superposition of the cores of 10 and the P(N) cluster affords a weighted rms deviation in atom positions of 0.33 A. Cluster 10 and [(Tp)(2)Mo(2)Fe(6)S(9)(SH)(2)](3-), prepared by a related route (Zhang, Y.; Holm, R. H. J. Am. Chem. Soc. 2003, 125, 3910-3920), demonstrate that the topology of the P(N) cluster can be achieved in molecular form in the absence of protein structure (Tp = tris(pyrazolyl)hydroborate).

Crystallography, X-Ray↗
PubMed2002

Rearrangement of symmetrical dicubane clusters into topological analogues of the P cluster of nitrogenase: nature's choice?

Reaction schemes have been developed that lead to clusters having the topology of the PN cluster of nitrogenase. The single cubane clusters [(Tp)MFe3S4Cl3]z (M = Mo, z = 1-; M = V, z = 2-) react with PEt3 to give [(Tp)MFe3S4(PEt3)3]1+, which are reduced to the neutral edge-bridged double cubanes [(Tp)2M2Fe6S8(PEt3)4] with highly reduced (2[MFe3S4]1+) cores. Reaction of these clusters in acetonitrile with (Et4N)(HS) results in the formation of [(Tp)2Mo2Fe6S9(SH)2]3- and [(Tp)2V2Fe6S9(SH)2]4-. X-ray structures of the Et4N+ salts reveal the bridging pattern M2Fe6(mu2-S)2(mu3-S)6(mu6-S) in which two cuboidal MFe3(mu3-S)3 units share the common bridge atom mu6-S and are externally bridged by two mu2-S atoms. The M sites possess trigonal octahedral, and the Fe sites, distorted tetrahedral coordination. Hydrosulfide ligands and sulfide atoms simulate terminal cysteinate ligation and mu2 bridges, respectively, in the protein-bound cluster Fe8S7(mu2-SCys)2(SCys)4. The synthetic clusters have the same bridging pattern as the PN cluster and approach congruency with it. These clusters are the first molecular topological analogues of a PN cluster. Like the latter, they are substantially reduced (majority of Fe(II)).

Biomimetic Materials↗