Two novel vanadium(III) complexes: V(dipic)(Hbdc)(H2O)2 (1) and [V2(dipic)2(H2btec)(H2O)4]·2H2O (2) (H2dipic = 2,6-pyridinedicarboxylic acid, H2bdc = 1,3-benzene-dicarboxylic acid, H4btec = 1,2,4,5-benzenetetracarboxylic acid) are synthesized by the reaction of V2(SO4)3, 2,6-pyridinedicarboxylic acid and 1,3-benzene-dicarboxylic acid (for 1) or 1,2,4,5-benzenetetracarboxylic acid (for 2) under hydrothermal condition at 120 °C for 3 days. They were characterized by elemental analysis, IR, UV-Vis, single crystal X-ray diffraction analysis and thermogravimetric analyses (TG). Structural analyses show that the vanadium atoms in the complexes 1 and 2 are both in a pentagonal-bipyramidal coordination environment with the NO6 donor set, and there is intermolecular hydrogen bonding in each complex. Research results found that the complexes exhibited bromination catalytic activity in the single-pot reaction of the conversion of phenol red to bromophenol blue in the mixed solution of H2O-DMF at the constant temperature of 30 ± 0.5 °C with pH = 5.8, and catalytic C-H bond cleavage activity for the peroxidative oxidation (with hydrogen peroxide) of cyclohexane to cyclohexanol and cyclohexanone (the maximum total turnover number is 395) under the mild conditions.

Based on mimicking the environment of the active center of vanadium haloperoxidase( V-HPOs),we designed and synthesized two kinds of peroxovanadium complexes: Na[VO( O2)2( C10H8N2) ]·8H2O( 1)and K3H [( VO)2( O2)4( μ2-O) ]·H2O( 2),which were structurally characterized by X-ray single crystal diffraction,elemental analysis,IR and UV-Vis spectroscopies. Structural analyses reveal that complex 1crystallized in an triclinic system with space group P-1,a = 0. 7213( 2) nm,b = 1. 1269( 4) nm,c = 1. 3728( 4) nm,α = 68. 349( 4) °,β = 89. 178( 4) °,γ = 88. 050( 4) °,V = 1. 0365( 6) nm3 and the complex 2 crystallized in an monoclinic system with space group P21/ c, a = 0. 67047( 12) nm,b = 0. 99503( 18) nm,c = 1. 5817( 3) nm,α = γ = 90°,β = 93. 739( 2) °,V = 1. 0530( 3) nm3. Complex 1 has a distorted pentagonal bipyramidal geometry,while complex 2 has a distorted octahedron geometry. In addition,by studying the bromination reaction activity,it shows that the peroxovanadium complexes can be considered as a potential functional model of bromoperoxidase.

Two oxo-vanadium(IV) complexes, [VO(C2O4)(2,2'-bipy)(H2O)]center dot C2H5OH(1) and VO(C2O4)(phen)(H2O) (2), where 2,2'-bipy=2,2'-bipyridyl, phen=1,10-phenanthroline, were synthesized as potential functional models of vanadium haloperoxidases(VHPOs) in mixed solvent of ethanol and water at room temperature. The complexes were characterized by elemental analysis, infrared(IR), UV-Vis and X-ray crystallography. Structural analyses showed that vanadium atom was coordinated by a terminal oxygen, one oxygen atom from coordinated water, two oxygen atoms from the carboxylate group of oxalic acid, and two nitrogen atoms(N1 and N2) from 2,2'-bipy/phen. Central vanadium atoms in complexes 1 and 2 were both in a distorted-octahedral environment, and some intermolecular hydrogen bonding linkages were also observed in each complex. Bromination reaction activity of the two complexes was evaluated with phenol red as organic substrate in the presence of H2O2, Br- and phosphate buffer, indicating that they can be considered as a potential functional model of VHPO. In addition, thermal analysis was also performed and discussed in detail.

Three new scorpionate nickel complexes [Tp*Ni(Hglu)(H2O)]·EtOH (1), Tp*Ni(Haze)(MeOH) (2), and Tp*Ni(HTA)(H2O) (3) (Tp* = hydrotris(3,5-dimethylpyrazolyl)borate) with different spanning dicarboxylo co-ligands (H2glu = glutaric acid, H2aze = azelaic acid, H2TA = tetradecane diacid) were synthesized by solution methods at room temperature. X-ray crystallographic analyses of complexes 1–3 demonstrate that these three octahedral Ni scorpionate complexes each contain an anionic chelating dicarboxylic acid, O2C(CH2) n COOH, n = 3, 7, and 12, respectively. The sixth coordination site is occupied by an ethanol, methanol, or water that is hydrogen bonded to the terminal carboxylic acid end of the anionic dicarboxylic acid ligand from a different Tp*Ni complex in the crystal lattice. Through these abundant hydrogen bond interactions, complexes 1 and 2 form 2D hydrogen bonding network structures, respectively, while complex 3 has a 1D infinite double-chain structure. The results of quantum mechanical calculations and thermogravimetric analyses on these complexes are presented and discussed.

A series of new nickel complexes, namely [Tp*Ni(sub)]·EtOH (1), [Tp*Ni(ad)]·EtOH (2), [Tp*Ni(seb)(H2O)] (3), and [Tp*Ni(μ–suc)NiTp*(MeOH)2] (4) (Tp* = hydrotris(3,5-dimethylpyrazolyl)borate, H2sub = suberic acid, H2ad = adipic acid, H2seb = sebacic acid, H2suc = succinic acid), were synthesized in mixed solvents at room temperature. The complexes were characterized by physico-chemical and spectroscopic methods. In addition, X-ray crystal structure analysis indicates that the four complexes share a common scorpionate (Tp*) Ni core with different aliphatic dicarboxylic acid ligands, and the nickel atom is in a distorted octahedral environment with the N3O3 donor set. Surface voltage spectroscopy indicates that these complexes exhibit surface photovoltage responses in the range of 300–800 nm, which can be assigned to LMCT and d → d * electronic transitions. In addition, quantum chemistry calculations on the complexes were performed and are discussed.

Based on mimicing the N,O coordination environment of the active center of vanadium haloperoxidase (V-HPOs) and the hydrogen-bond interaction between the active center and amino acid residues or water molecules,we designed and synthesized two kinds of oxidovanadium complexes:(C3H5N2)2[(VO)2(μ2-C2O4)(C2O4)2(H2O)2] (1) and (VO2)2(μ2-C2O4)(C3H4N2)2 (2).We determined their structures by X-ray single crystal diffraction.The crystal structure analysis indicated that the coordination environments of those oxidovanadium complexes were similar to the active center of vanadium haloperoxidase,and there seemed to be a mimicing α-helix structure in the three-dimensional packing structure of the complexes.Additionally,by studying the bromination reaction activity we found that the oxidovanadium complexes had an upper activity during the mimic catalytic process.

Vanadium complexes with poly（pyrazolyl）borate ligands have received an increasing attention in the field of mimicking catalysis.A part of poly（pyrazolyl）borate ligands and their vanadium complexes were summarized,and their research progress on synthesis,structure and properties and promising application in medical field were discussed.

In order to mimic the active center of the V-HPOs, we designed and synthesized a series of oxovanadium complexes containing poly (pyrazolyl) borate ligands: VO(HB(3,5-Me(2)pz)(3)) (3,5-Me(2)pz) (HOOC-CH2CH2COO) (1) and VO(HB(3,5-Me(2)pz)(3)) (3,5-Me(2)pz) (C5H4N-COO) (2), which were characterized by X-ray single crystal diffraction. Based on the characteristics that vanadium(V) complexes catalyze phenol red oxidation of bromide into bromophenol blue in a water system under weak-acid condition, the study on catalytic activity about scorpionate oxovanadium(IV) complexes was preformed. The result shows that the scorpionate oxovanadium(IV) complexes exhibit catalytic activity to the extent under the similar conditions. The mechanism of the catalytic reaction was analyzed by molecular orbital theory.

Two new half-sandwich monomeric complexes of oxovanadium (IV), Tp*VO(OOCHCCHCOOCH3)(pz*H) (1) and Tp*VO(DMSO)(NCS) (2) (Tp*.hydrotris(3,5-dimethylpyrazolyl)borate, pz*H=3,5-dimethylpyrazole) have been synthesized from the reaction of VOSO4 center dot nH(2)O with respective ligands. The complexes were characterized by element analysis, IR spectra and single crystal X-ray diffraction. The electronic structure and the bonding characters of the two complexes were analyzed with ab initio calculations. The calculations results showed that the structural stability of complexes 1 and 2 are close. The atomic net charge distribution in the molecular system indicates obvious covalent interaction between the coordinated atoms (N, O) and vanadium. The results are consistent with the structural analysis of complexes. CCDC: 784501, 1; 784502, 2.

A new family of aminoacid-derivatized oxidovanadium complexes as potential functional model of vanadium haloperoxidases: [VVO(sal-phe)(OMe) (MeOH)] (1), [VIVO(sal-ala)(2,2′-bipy)]·H2O (2), [VIVO(sal-ala)(1,10-phen)]·0.5H2O (3) and [VIVO(sal-his)(1,10-phen)]·2MeOH (4) (H2sal-phe=Schiff base derived from salicylaldehyde and dl-β-phenylalanine, H2sal-ala=Schiff base derived from salicylaldehyde and dl-α-alanine, H2sal-his=Schiff base derived from salicylaldehyde and l-histidine) have been synthesized. All the complexes were characterized by elemental analysis, IR spectra and UV–Vis spectroscopy. In particular, molecular structures of three representative complexes (1, 2 and 3) were determined by X-ray crystallography. In addition, bromination reaction activity of the starting material and the complexes has been tested by a method with phenol red as organic substrate in the presence of H2O2, Br− and phosphate buffer, the studying results indicate that the vanadium complexes can catalyze the visible conversion of phenol red to bromophenol blue under weak-acid conditions and the different structural characterizations of the complexes exhibit different catalytic activity, therefore, the complexes can be considered as a potential functional model of VHPO.

Based on the 2,6-pyridinedicarboxylate acid ligand, ten lanthanide complexes with formula, (Hdipa)3[Ln(L)3] (Ln = Eu [1], Gd [2], Nd [3], Tb [4], Ce [5], Sm [6], Pr [7], Dy [8] and Er [9]) and [Nd(L)(HL)(H2O)2]·4H2O (10), (where H2L = 2,6-pyridinedicarboxylic acid and dipa = N-(1-methylethyl)-2-propanamine) have been prepared by different synthetic methods. Structural analyses reveal that complexes 1–3 are isomorphous, zero-dimensional structures, which are further connected to 3D H-bonding networks via extensive intermolecular hydrogen bonds. In the structures of these complexes, the dipa plays a key role in balancing electric charge. For complex 10, the 1D Ln–O–C–O–Ln polymeric chains are linked into a stable 3D H-bonding framework through numerous intermolecular and intramolecular hydrogen bonds. The luminescent properties of complexes 1, 4, 6 and 8 were investigated in detail.

A series of oxovanadium(IV) complexes: TpVO(pzH)(2,4-Cl–C6H3–OCH2COO) (1), TpVO(pzH)(C6H5–OCH2COO) (2), TpVO(pzH)(p-Cl–C6H4–COO) (3), TpVO(pzH)(3,5-NO2–C6H3–COO) (4), Tp∗VO(pzH∗)(p-Cl–C6H4–COO) (5) and Tp∗VO(pzH∗)(p-Cl–C6H4–COO) · CH3OH (6) (Tp = hydrotris(pyrazolyl)borate, pzH = pyrazole, Tp∗ = hydrotris(3,5-dimethylpyrazolyl)borate, pzH∗ = 3,5-dimethylpyrazole) were synthesized and their crystal structures were determined by X-ray diffraction. In all the complexes, the vanadium ions are in a distorted-octahedral environment with a N4O2 donor set. Hydrogen bonding interaction exists in each complex. Complexes 1 and 2 are hydrogen-bonded dimers. Dimeric units of 2 are connected to one another via weak inter-molecular C–H···O interactions to form a 2D network on the bc-face. In 3–6 there exist intramolecular N–H···O hydrogen bonds between the neutral pyrazole/3,5-dimethylpyrazole and the uncoordinated carboxyl oxygen atom. In addition, the catalytic activity of complex 2 in a bromination reaction in phosphate buffer with phenol red as a trap was evaluated by UV–Vis spectroscopy. Furthermore, the elemental analyses, IR spectra and thermal stabilities were recorded.

Two new oxidovanadium (IV) complexes: TpVO(L1) (1) and Tp*VO(pzH*)(L2) (2) [Tp = hydrotris(pyrazolyl)borate, HL1 = 5-methyl-1H-pyrazole-3-carboxylic acid, Tp* = hydrotris(3,5-dimethylpyrazolyl)borate, pzH* = 3,5-dimethylpyrazole, HL2 = 5-phenyl-1H-pyrazole-3-carboxylic acid] have been synthesized and characterized by elemental analysis and IR spectroscopy. The single-crystal structures of the complexes shows that the vanadium ion is in a distorted octahedral environment with a N4O2 donor set in each complex. Additionally, hydrogen bonding interaction exits in both complexes. Interestingly, the molecules of 1 are held together to form a 1D hydrogen bonded polymer along the b axis, whereas complex 2 is a hydrogen bonded dimer. In addition, the catalytic activities of complexes 1 and 2 in bromination reactions in phosphate buffer with phenol red as a trap were evaluated primary by UV/Vis spectroscopy. Furthermore, ab initio calculations of complexes 1 and 2 were performed.

A series of oxo-vanadium(IV) complexes: Tp∗VO(pzH∗)(CH3COO) (1), Tp∗VO(pzH∗)(CCl3COO) (2), Tp∗VO(pzH∗)(C6H5COO) (3), Tp∗VO(pzH∗)(m-NO2–C6H4COO)·CH3CN (4) and [Tp∗VO(pzH∗)(H2O)]+[m-NO2–C6H4–SO3]−·CH3OH (5) (Tp∗=hydrotris(3,5-dimethylpyrazolyl)borate; pzH∗=3,5-dimethylpyrazole) are synthesized in methanol solution under physiological conditions. They are characterized by elemental analysis, IR, UV–Vis and X-ray crystallography. Structural analyses show that the vanadium atoms in complexes 1–5 are all in a distorted-octahedral environment with the N4O2 donor set, and intra- or inter-hydrogen bonding linkages have been also observed in each complex. Bromination reaction activity of the complexes has been evaluated by the method with phenol red as organic substrate in the presence of H2O2, Br− and phosphate buffer, indicating that they can be considered as potential functional model vanadium-dependent haloperoxidases. In addition, thermal analysis and quantum chemistry calculations were also performed and discussed in detail.

Three new oxidovanadium complexes as potential functional model vanadium-dependent haloperoxidases: [VO2(C9H7NO3)](C10H10N2)0.5 (1), [VO(C10H8N2)(C9H7NO3)]3 (2) and [VO(C12H8N2)(C9H7NO3)]·2.33H2O (3) have been designed and synthesized under room temperature with mixed solution of CH3OH and H2O. All the complexes have been characterized by elemental analysis, IR spectra, UV–vis spectroscopy and X-ray single crystal diffraction. The structural analysis indicates that the three complexes are all containing a tridentate amino-Schiff-base (salicylideneglycinate) with imine nitrogen, phenoxyl, and carboxyl oxygen as three donor atoms. The asymmetric unit of complex 1 is formed by one [VO2(C9H7NO3)]– anion and half of (C10H10N2)2+ cation, in which the nitrogen atoms of 4,4′-bipy were protonated. For complex 1, the coordination environment of the central vanadium atom is almost ideal square pyramid, while for complexes 2 and 3, the vanadium atom is a six-coordinated and in a distorted octahedral environment. It is found that there are a variety of inter- and intra-molecular hydrogen bonds in all the three complexes. What is intriguing to us is that the oxidation state of the central metal atom in complex 1 is different from that of complex 2 and 3: the oxidation state of vanadium in complex 1 is +5, while ones in complex 2 and 3 are +4. Bromination reaction activity of the complexes has been evaluated by the method with phenol red as organic substrate in the presence of H2O2, Br– and phosphate buffer, indicating that they can be considered as potential functional model vanadium-dependent haloperoxidases. In addition, thermal analysis, cyclic voltammetry and quantum chemistry calculations were also performed and discussed in detail.

Complexes of melamine with adipic acid and Cu(CH3COO)2 center dot H2O, [Cu2(MA)(ad)2] center dot H2O (1), and (MA) center dot (H2ad) center dot H2O (2) (MA = melamine; H2ad = adipic acid) have been synthesized under hydrothermal conditions and characterized by elemental analysis, infrared, UV-Vis, and single crystal X-ray diffraction. Both crystallized in the triclinic space group P-1. In 1, MA and adipate bond to copper to construct a 3-D supramolecular framework in an unusual noninterpenetrated pseudo-primitive cubic topology constructed from a four-connected binuclear Cu(II) secondary building unit. A variety of intra- or inter-molecular hydrogen bonds exist. In 2, the 3-D supramolecular structure is formed through strong interactions among MA, adipic acid, and lattice water. Thermal analysis, photoluminescence, and calculations were also performed.

A mixing solution of the prepared acetylferrocene and S-benzyl-N-Dithiocarbazate in ethanol with 1∶1 mole ratio is kept on reflux in water bath.Then the goal compound S-benzyl-N,N'-(ferrocenyl-1-methyl-metylidene)-Dithiocarbazate(HLSB)is obtained.The structure of title amplex is characterized by IR spectra,UV spectra.A Schiff base compound with phenyl-and ester alkyl is synthesized.The compound consist of one-dimensional chain that is linked together by a kind of weak H-bonding(N1-H1B——S1A(-x+1,y+1/2,-z+1/2)).