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1.
N-Alkyl-N,N-di(2-pyridylmethyl)amines are ligands commonly used by supramolecular chemists in molecular recognition and sensing applications. The metal coordination complexes of these ligands, in particular those with 2:1 (ligand:metal) molar ratio, have not been sufficiently characterised in solution. In this work, bis[N-alkyl-N,N-di(2-pyridylmethyl)amine]zinc(II) perchlorates are characterised in both solid and solution phases, using X-ray crystallography and NMR spectroscopy, respectively. Only the cis-facial stereoisomer is observed. Density functional theory calculations support the thermodynamic preference for this stereochemistry, as in one representative case the gas phase energy of the cis-facial configuration is lower than those of the trans-facial and meridional configurations by 4.0 and 4.5 kcal/mol, respectively.  相似文献   

2.
[Cu(bpea)Cl]ClO4 (1) and a new copper(II) complex [Cu(bpma)(Ph-COO)(H2O)]ClO4 (2) [bpea?=?N,N-bis(2-pyridylmethyl)ethylamine; bpma?=?N,N-bis(2-pyridylmethyl)methylamine] have been synthesized. Complex 2 was crystallized in monoclinic space group P21/c with unit cell parameters a ?=?16.460(6)?Å, b ?=?11.222(4)?Å, c?=?12.522(5)?Å, and β?=?97.985(6)°. Interactions of the complexes with calf thymus DNA (CT-DNA) have been investigated by UV absorption, fluorescence, and cyclic voltammetry; thus, modes of CT-DNA binding for the complexes have been proposed. Furthermore, DNA cleavage activities by the complexes were performed in the absence of any external agents. The influence of complex concentration or reaction time on the DNA cleavage was studied.  相似文献   

3.
Two new branched pentadentate amines (N5), 3,7-bis(2-pyridylmethyl)-5,5-dimethyl-3,7-diazaheptane-1-amine (1) and 4,8-bis(2-pyridylmethyl)-6,6-dimethyl-4,8-diaza octane-1-amine (2) have been prepared. These have been used to synthesis two new Schiff base complexes containing a pyridine and 2-pyridylmethyl pendant arm, by template [1+1] condensation of pyridine-2-carbaldehyde with the amines in the presence of Mn(II) in methanol. Elemental and spectral results are used to characterize the complexes and their structures are confirmed by single crystal X-ray diffraction studies. The structure of MnL1(ClO4)2 indicates that in the solid state the Mn(II) ion adopts a slightly distorted octahedral geometry. The crystal structure of [Ni(1)(MeCN)](ClO4)2 is also reported and exhibits a slightly distorted octahedral geometry. Also the synthesized complexes were screened for their antibacterial activity against Escherichia coli (Lio), Serratia marcescens (PTCC 1330), Staphylococcous aureus (ATCC 6633), and Proteus vulgaris (Lio) and results showed that the all complexes have antibacterial effects and [NiL1](ClO4)2, [MnL2](ClO4) and [MnL1](ClO4)2 have more effective ones against E. coli.  相似文献   

4.
合成和表征了5个螺旋配位聚合物{[Cu(Hbpma)(H2O)4]2(SO4)3·3.5H2O}n (1)、{[Ni(Hbpma)(H2O)4]4(SO4)6·10.75H2O}n (2)、{[Mn(Hbpma)(H2O)4](SO4)1.5·3H2O}n (3)、{[Zn(Hbpma)(H2O)4]4(SO4)6·4H2O·4CH3OH}n (4)和{[Cu(Hbpma)2(H2O)2](SO4)2·9H2O}n (5), 其中bpma代表N,N'-双(3-吡啶甲基)胺。晶体结构分析表明配合物1~4为一维链状结构, 配合物5为二维层状结构, 其中金属离子由质子化的bpma配体桥连。值得注意的是, 采取反-反式构象的柔性bpma配体使得配合物12为假螺旋链结构, 配合物34为螺旋链结构, 配合物5为螺旋层结构。同时研究了配合物的磁性和热稳定性。  相似文献   

5.

A new dinuclear nickel(II) compound, [Ni2(TPA)2(μ-C2O4)](H2O)0.75(ClO4)2 [TPA = tris(2-pyridylmethyl) amine], was synthesized and characterized by electronic spectroscopy and X-ray methods. In the complex, the oxalate ion acts as a bis-bidentate ligand and the two Ni(II) ions are six coordinated with a distorted octahedral structure. The complex crystallizes in the triclinic space group Pi , with a = 13.203(4), b = 16.574(5), c = 21.802(6) Å, α = 78.644(5), β = 80.299(5), γ = 72.446(5)°, V = 4429 Å3, Z = 2; R 1 = 0.0615, wR 2 = 0.1639. In the temperature range 4-300 K, magnetic measurements show that the exchange interaction between the two metal ions is antiferromagnetic with J = ? 18.74 cm?1, g = 2.10.  相似文献   

6.
Reaction of the N-(2-pyridyl)carbonylaniline ligand (L) with Cu(NO3)2, Cu(ClO4)2, Zn(ClO4)2, Ni(NO3)2 and PdCl2 gives complexes with stoichiometry [Cu(L)2(H2O)2](NO3)2, [Cu(L)2(H2O)2](ClO4)2, [Zn(L)2(H2O)2] (ClO4)2, [Ni(L)2(H2O)Cl](NO3) and PdLCl2. The new complexes were characterized by elemental analyses and infrared spectra. The crystal structures of [Cu(L)2(H2O)2](NO3)2, [Cu(L)2(H2O)2](ClO4)2, and [Zn(L)2(H2O)2](ClO4)2 were determined by X-ray crystallography. The cation complexes [M(L)2(H2O)2] contain copper(II) and zinc(II) with distorted octahedral geometry with two N-(2-pyridyl)carbonylaniline (L) ligands occupying the equatorial sites. The hexa-coordinated metal atoms are bonded to two pyridinic nitrogens, two carbonyl oxygens and two water molecules occupying the axial sites. Both the coordinated water molecules and uncoordinated amide NH groups of the N-(2-pyridyl)carbonylaniline (L) ligands are involved in hydrogen bonding, resulting in infinite hydrogen-bonded chains running in one and two-dimensions.  相似文献   

7.
合成和表征了5个螺旋配位聚合物{[Cu(Hbpma)(H2O)4]2(SO4)3·3.5H2O}n (1)、{[Ni(Hbpma)(H2O)4]4(SO4)6·10.75H2O}n (2)、{[Mn(Hbpma)(H2O)4](SO4)1.5·3H2O}n (3)、{[Zn(Hbpma)(H2O)4]4(SO4)6·4H2O·4CH3OH}n (4)和{[Cu(Hbpma)2(H2O)2](SO4)2·9H2O}n (5),其中bpma代表N,N'-双(3-吡啶甲基)胺。晶体结构分析表明配合物1~4为一维链状结构,配合物5为二维层状结构,其中金属离子由质子化的bpma配体桥连。值得注意的是,采取反-反式构象的柔性bpma配体使得配合物12为假螺旋链结构,配合物34为螺旋链结构,配合物5为螺旋层结构。同时研究了配合物的磁性和热稳定性。  相似文献   

8.
Six mononuclear complexes are reported with the tetradentate ligand N,N′-bis(2-pyridylmethyl)-1,3-propanediamine, (abbreviated as pypn) i.e. [Cu(pypn)(ClO4)2](H2O)1/2 (1), [Fe(pypn)Cl2](NO3) (2), [Zn(pypn)Cl](ClO4) (3), [Co(pypn)(NCS)2](ClO4) (4), [Co(pypn)(N3)2](ClO4) (5), [Zn(pypn)(NCS)2] (6). The synthesis and X-ray crystal structures of all six compounds and their spectroscopic properties are presented.The geometry of the Cu2+, Co3+, Zn2+, Fe3+ ions is essentially octahedrally based, with the mm conformation (for Cu) and msf conformations for the other 3 metal ions; in compound 3 the geometry around the Zn2+ is distorted trigonal bipyramidal. The stabilisation of the crystal lattices is maintained by interesting, relative strong hydrogen bonds.  相似文献   

9.
Tetradentate Schiff-base carboxylate-containing ligands, bis(2-pyridylmethyl)amino-5-valeric acid (Hpmva) and bis(2-pyridylmethyl)amino-6-caproic acid (Hpmca), react with copper(II) perchlorate to give rise to the carboxylated bridged chain complexes {[Cu(μ-pmva)(H2O)](ClO4)}n (1) and {[Cu(μ-pmca)(H2O)](ClO4)}n (2). These complexes have been characterized by X-ray crystallography, spectroscopic, and variable-temperature magnetic susceptibility measurements. In 1 and 2, each of the copper(II) ions exhibit CuN3O2 coordination environments with the three nitrogen atoms of the ligand and one oxygen atom belonging to the carboxylate group of an adjacent molecule occupying the basal position and a water molecule coordinated in the axial position. The electronic spectra of the complexes are significantly affected by the coordination geometry. Magnetic susceptibility measurements indicate that complexes exhibit very weak ferromagnetic interactions.  相似文献   

10.
Three new Mn(II) bis(pendant arm)-macrocyclic Schiff base complexes, [MnLn]2+(n = 1, 2, 3), have been prepared via cyclocondensation of 2,6-diacetylpyridine with three different branched hexadentate amines (3,6-bis(2-pyridylmethyl)-3,6-diazaoctane-1,8-diamine (1), 3,7-bis(2-pyridylmethyl)-3,7-diazanonane-1,9-diamine (2) and 3,8-bis(2-pyridylmethyl)-3,8-diazadecane-1,10-diamine (3)) in the presence of MnCl2 in methanol. The ligands, L, are 15-, 16- and 17-membered pentaaza macrocycles having two 2-pyridylmethyl pendant arms [L1; 2,13-dimethyl-6,9-bis(2-pyridylmethyl)-3,6,9,12,18-pentaazabicyclo[12.3.1]octadeca-1(18), 2, 12, 14, 16-pentaene, L2; 2,14-dimethyl-6,10- bis(2-pyridylmethyl)-3,6,10,13,19-pentaazabicyclo[13.3.1]nonadeca-1(19), 2, 13, 15, 17-pentaene and L3; 2,15-dimethyl-6,11-bis(2-pyridylmethyl)-3,6,11,14,20-pentaazabicyclo[14.3.1]eicosa-1(20),2,14,16,18-pentaene]. All the complexes have been characterized by physicochemical and spectroscopic methods. The crystal structure of [MnL1](ClO4)2·CH3CN has been determined and indicates that in the solid state, the complex adopts a slightly distorted pentagonal bipyramidal geometry with the Mn(II) centre located within a pentaaza macrocycle with two 2-pyridylmethyl pendants coordinating in the axial positions.  相似文献   

11.
Two new complexes [CuBr(C11H13N2O)] (1) and [Cu(NCO)(C11H13N2O)] (2) containing the tridentate Schiff base ligand, N-(1-acetyl-2-propylidene)(2-pyridylmethyl) amine which is the 1:1 condensation product of acetylacetone and 2-aminomethylpyridine, have been synthesised and characterised by elemental analysis, IR and electronic spectra, electrochemical study and single crystal X-ray diffraction study. Crystal structures reveal that the copper atom in both the complexes are in square geometry formed by the N2O donor set of the Schiff base and a bromine atom in 1 and one cyanate ligand in 2. Both bromide and isocyanate ligands act in a terminal monodentate fashion.  相似文献   

12.
Two new mononuclear cobalt(II) complexes [Co(ntb)(pic)](ClO4) · (CH3OH)2.35 (1) and [Co(ntb)(nic)](ClO4) · CH3OH (2) were synthesized and structurally characterized, where ntb is tris(2-benzimidazolylmethyl)amine, pic is the anion of picolinic acid, and nic is the anion of nicotinic acid. The X-ray analysis indicates that the Co(II) center is six-coordinate in distorted octahedral and five-coordinate in distorted trigonal bipyramidal geometry for 1 and 2, respectively. In 1, the picolinate anion coordinates to Co(II) in a bidentate μ2-N,O chelating mode. In 2, the nicotinate anion coordinates with Co(II) through a monodentate carboxylate oxygen. 1-D chain structures were formed by intermolecular hydrogen bonds in the two complexes and π–π interactions are important for the stabilization of the structures.  相似文献   

13.
The ligand 1,1,3,3-tetramethylbutylisocyanide, CNCMe2CH2CMe3, i.e. t-octylisocyanide, with Co(ClO4)2 · 6H2O or Co(BF4)2 · 6H2O in ethanol, produces pentakis(alkylisocyanide)cobalt(II) complexes, [Co(CNC8H17-t)5](ClO4)2 (1) and [Co(CNC8H17-t)5](BF4)2 · 2.0H2O (2). These Co(II) complexes undergo reduction/substitution upon reaction with trialkylphosphine ligands to produce [Co(CNC8H17-t)3{P(C4H9-n)3}2]ClO4 (3), [Co(CNC8H17-t)3{P(C4H9-n)3}2]BF4 (4), and [Co(CNC8H17-t)3{P(C3H7-n)3}2]ClO4 (5). Complex 3 is oxidized with AgClO4 to produce [Co(CNC8H17-t)3{P(C4H9-n)3}2](ClO4)2 (6). Complex 1 yields [Co(CNC8H17-t)4py2](ClO4)2 (7) upon dissolving in pyridine. Reactions with triarylphosphine and triphenylarsine ligands were unsatisfactory. The chemistry of 1 and 2 is therefore more similar to that of Co(II) complexes with CNCMe3 than with CNCHMe2, other alkylisocyanides, or arylisocyanides, but shows some behavior dissimilar to any known Co(II) complexes of alkylisocyanides or arylisocyanides. Infrared and electronic spectra, magnetic susceptibility, molar conductivities, and cyclic voltammetry are reported and compared with known complexes. 1H, 13C, and 31P NMR data were also measured for the diamagnetic complexes 3, 4, and 5.  相似文献   

14.

This article reports the synthesis and crystal structures of two new mononuclear Zinc(II) complexes, [Zn2(NTB)2(N3)2](NO3)2·2CH3OH (1) and [Zn2(NTB)2(SCN)2](NO3)2·2CH3OH·H2O (2). Complex 1 crystallizes in the triclinic system, space group P&1macr;, a=13.743(4), b=14.374(4), c=14.443(5) Å; α=77.053(5), β=81.824(5), γ=88.959(6)°; Z=2; R1=0.0418, wR2=0.0889. Complex 2 also crystallizes in the triclinic system, space group P&1macr;, a=12.203(10), b=14.430(12), c=18.541(15)Å; α=72.712(15), β=85.039(15), γ=73.610(14); Z=2; R1=0.0771, wR2=0.1288. In both cases the central zinc(II) metal ions are coordinated to the four nitrogen atoms of NTB and a nitrogen atom of N- 3(1) or SCN-(2) to form distorted trigonal bipyramidal coordination spheres.  相似文献   

15.
Three new branched hexadentate amines (N6), 3,6-bis(2-pyridylmethyl)-3,6-diazaoctane-1,8-diamine (1), 3,7-bis(2-pyridylmethyl)-3,7-diazanonane-1,9-diamine (2) and 3,8-bis(2-pyridylmethyl)-3,8-diazadecane-1,10-diamine (3) have been synthesized. Subsequently, three novel Schiff base macrocyclic complexes containing a phenanthroline and two 2-pyridylmethylpendant arms have been prepared by template [1+1] cyclocondensation of 2,9-dicarboxaldehyde-1,10-phenanthroline and the branched hexadentate amines (13), in the presence of Mn(II) in methanol. These complexes have ligands with 18-, 19- and 20-membered hexaaza macrocycles and two 2-pyridylmethyl pendant arms (L1, L2 and L3, respectively). All the complexes have been characterized by elemental analysis and IR spectroscopy. The crystal structure of [MnL1](ClO4)2 · 3CH3CN was determined and indicates that in the solid state the complex adopts a slightly distorted hexagonal bipyramidal geometry with the Mn(II) ion located within a hexaaza macrocycle with the two 2-pyridylmethyl pendant arms coordinating in axial positions.  相似文献   

16.
A five-coordinate copper(II) complex with the tripod ligand tris(N-methylbenzimidazol-2-ylmethyl)amine (Mentb) and salicylate, with the composition [Cu(Mentb) (salicylate)](ClO4) · 2DMF, was synthesized and characterized by elemental and thermal analyses, electrical conductivity, IR and UV-Vis spectral measurements. The crystal structure of the complex has been determined by single-crystal X-ray diffraction. The Cu(II) is five-coordinate with four N atoms from the Mentb ligand and an O atom of the monodentate salicylate ligand. The N4O donors are in a distorted trigonal-bipyramid geometry. Cyclic voltammograms indicate a quasireversible Cu2+/Cu+ couple. The X-band EPR spectrum of the complex confirms the trigonal-bipyramidal structure with g < g and a very small value of A (41 × 10?4 cm?1).  相似文献   

17.

Oxo-bridged diiron(III) complexes [Fe2O(L1)2(H2O)2](ClO4)4 (1) and [Fe2O(L2)2(H2O)2](ClO4)4 (2), where L1 and L2 are tetradentate N-donor N,N′-bis(2-pyridylmethyl)-1,2-cyclohexanediamine and N,N′-bis(2-pyridylmethyl)ethane-1,2-diamine respectively, have been isolated as synthetic models of non-heme iron oxygenases and characterized by physicochemical and spectroscopic methods. Both the complexes have been studied as catalysts for the oxyfunctionalization of saturated hydrocarbons using green hydrogen peroxide (H2O2) as oxidant under mild conditions. The selectivity (A/K) and regioselectivity (3°/2°) in oxidative C–H functionalization of alkanes suggests the involvement of metal-based intermediate in the oxygenation reaction. The catalytic efficiency is found to be strongly dependent on the presence of acetic acid. Remarkable increase in conversion and selectivity favoring the formation of alcohols in the oxidation of cyclohexane and cyclooctane and exclusive hydroxylation of adamantane with drastic enhancement of regioselectivity has been achieved by the addition of acetic acid in the presence of H2O2.

  相似文献   

18.
Three complexes, [Mn(bpp)4(H2O)2](ClO4)2?·?1.5H2O (1), [Mn(bpp)3Br2]?·?2H2O (2), and [Mn(bpp)2(H2O)2](ClO4)?·?I?·?H2O?·?bpp (3) (bpp?=?1,3-bis(4-pyridyl)propane), were synthesized and structurally characterized by single-crystal X-ray diffraction. Complex 1 is mononuclear where M(II) is coordinated to a monodentate TT-bpp, three monodentate TG-bpp, and two water molecules. Complex 2 possesses a single-stranded helical chain formed from MnN4Br2 octahedra by a single TT-bpp, with pendant monodentate TG-bpp ligands. Complex 3 consists of a ribbon-type double-stranded chain formed from MnN4O2 octahedra by double TG-bpp ligands. 2-D supramolecular architectures of 13 are formed by hydrogen bonds. The fluorescence of the three complexes comes from the π*–π transition of the ligand.  相似文献   

19.
The title compounds, bis{μ‐N‐[(diphenylphosphanyl)methyl]pyridin‐4‐amine‐κ2N1:P}disilver bis(perchlorate) acetonitrile monosolvate, [Ag2(C18H17N2P)2](ClO4)2·CH3CN, (1), and bis{μ‐N‐[(diphenylphosphanyl)methyl]pyridin‐4‐amine‐κ2N1:P}bis[(nitrato‐κ2O,O)silver], [Ag2(C18H17N2P)2(NO3)2], (2), each contain disilver macrocyclic [Ag2(C18H17N2P)2]2+ cations lying about inversion centres. The cations are constructed by two N‐[(diphenylphosphanyl)methyl]pyridin‐4‐amine (DPP) ligands linking two Ag+ cations in a head‐to‐tail fashion. In (1), the unique Ag+ cation has a near‐linear coordination geometry consisting of one pyridine N atom and one P atom from two different DPP ligands. Two ClO4 anions doubly bridge two metallomacrocycles through Ag...O and N—H...O weak interactions to form a chain extending in the c direction. The half‐occupancy acetonitrile molecule lies with its methyl C atom on a twofold axis and makes a weak N...Ag contact. In (2), there are two independent [Ag(C18H17N2P)]+ cations. The nitrate anions weakly chelate to each Ag+ cation, leading to each Ag+ cation having a distorted tetrahedral coordination geometry consisting of one pyridine N atom and one P atom from two different DPP ligands, and two chelating nitrate O atoms. Each dinuclear [Ag2(C18H17N2P)2(NO3)2] molecule acts as a four‐node to bridge four adjacent equivalent molecules through N—H...O interactions, forming a two‐dimensional sheet parallel to the bc plane. Each sheet contains dinuclear molecules involving just Ag1 or Ag2 and these two types of sheet are stacked in an alternating fashion. The sheets containing Ag1 all lie near x = , , etc, while those containing Ag2 all lie near x = 0, 1, 2 etc. Thus, the two independent sheets are arranged in an alternating sequence at x = 0, , 1, etc. These two different supramolecular structures result from the different geometric conformations of the templating anions which direct the self‐assembly of the cations and anions.  相似文献   

20.
The reaction of Cu(ClO4)2·6H2O and Cd(ClO4)2 with di-(2-picolyl)sulfur (dps) leads to the formation of mononuclear complexes [Cu(dps)(H2O)(ClO4)](ClO4) (1) and [Cd(dps)2](ClO4)2 (2). The crystal structure of 1 exhibits a distorted square pyramidal geometry, coordinated by one sulfur and two nitrogen atoms from the dps ligand, one water molecule and one perchlorate oxygen atom. For 2, the environment around cadmium atom is in a distorted octahedron with four nitrogen and two sulfur atoms from the dps ligand. Cyclic voltammetric data show that complexes undergo two waves of a one-electron transfer corresponding to M(II)/M(III) and M(II)/M(I) processes. Spectral and electrochemical behaviors of the complexes are also discussed.  相似文献   

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