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1.
Using a racemic mixture of the tridentate ligand, (((2-pyridyl)ethylamine)methyl)phenolate ion (L−) and , NCS−, (NC)2N−, OAc− as coligands, complexes having the formula [Ni(L)(N3)] (1), [Ni(L)(NCS)]2 (2), [Ni2(L)2(OAc)(N(CN)2)]n (3) were prepared and structurally characterized. In 1, Ni(II) has a square planar geometry and phenolate oxygen is involved in dipolar ?Nδ+ interaction with electrophilic central nitrogen atom of coordinated azide ion. Complex 2 is dimeric in nature and nickel(II) is penta-coordinated. Compounds 1 and 2 exist as centrosymmetric dimers made up of a pair of R and S enantiomers of L. In 3, an acetate and phenoxo bridged dinickel complex is present which is further linked to a zig-zag coordination polymer by the dicyanamide ion. In a given chain of 3, both L have same enantiomeric form and either RR or SS dimers are repeated along the chain. The magnetic properties are described. 相似文献
2.
Two new trinuclear complexes, Cu3L2(py)2 (1) and Ni3L2(py)4 (2), have been synthesized and characterized, where L3− is N-2-methyl-acryloyl-salicylhydrazidate. Central metal ion and two terminal metal ions in the two complexes are combined by two bridging deprotonated L3− ligands, forming a bent trinuclear structure unit with an M-N-N-M-N-N-M core. The bent angles in complexes 1 and 2 are 167.6(1)° and 75.4(1)°, respectively. Three nickel ions in compound 2 exhibit alternating square-planar and octahedral geometries, while three copper ions in compound 1 follow square-planar mode. The studies in solution integrity and stability of compounds 1 and 2 show they are soluble and stable in DMF. UV-Vis titrations demonstrate compound 1 is stable in DMF even in the presence of excess metal ions. Antibacterial screening data indicate the two compounds all have stronger antimicrobial activities against the tested microorganisms than ligand. The trinuclear copper compound 1 is more active than monocopper compounds in the previous study, and the trinuclear nickel compound 2 is less active than tetranuclear nickel compound in the previous study. 相似文献
3.
C Valan AmburoseTheivanayagam C Deivaraj Ghee Xiong LaiJeyagowry T Sampanthar Jagadese J Vittal 《Inorganica chimica acta》2002,332(1):160-166
We have utilized the possibility of altering the ratio of reactants to result in tetrahedral anions, [M(SC{O}Me)nCl4−n]2− (n=3, 4) and [Cd2Cl2(SC{O}Me)4]2−. Complexes of the formula [Ph4P]2[M(SC{O}Me)4] (M=Zn(II) (1), Cd(II) (2) or Hg(II) (3)) were synthesized by the reaction of thioacetate ligand with the metal salts and Ph4PCl in 4:1:2 molar ratio in suitable solvents. The geometry of Zn(II) in 1 is nearly tetrahedral and the distortion in tetrahedron increases in the order of 1<2<3 as observed from the SMS angles in the crystal structures. The tendency of monoanionic complexes [Ph4P][M(SC{O}Me)3] to react with 1 mole equivalent of Ph4PCl resulted in complexes of the type [Ph4P]2[M(SC{O}Me)3Cl] (M=Cd(II) (4) or Hg(II) (5)). In the structures of 4 and 5, three sulfur atoms and one chloride atom occupy the corners of the tetrahedron around the metal centers. However, in a 4:2:2 or 2:1:2 molar reaction of Me{O}CS− with CdCl2 and Ph4PCl in aqueous medium resulted in a chloro bridged dimer, [Ph4P]2[Cd2(μ-Cl)2(SC{O}Me)4] (6) as determined by X-ray crystallography. 相似文献
4.
The acid-base properties and Cu(II), Ni(II), Ag(I) and Hg(II) binding abilities of PAMAM dendrimer, L, and of the simple model compounds, the tetraamides of EDTA and PDTA, L1, were studied in solution by pH-metric methods and by 1H NMR and UV-Vis spectroscopy. PAMAM is hexabasic and six pKa values have been determined and assigned. PAMAM forms five identifiable complexes with copper(II), [CuLH4]6+, [CuLH2]4+, [CuLH]3+, [CuL]2+ and [CuLH-1]+ in the pH range 2-11 and three with nickel(II), [NiLH]3+, [NiL]2+ and [NiLH-1]+ in the pH range 7-11. The complex [CuLH4]6+, which contains two tertiary nitrogen and three amide oxygen atoms coordinated to the metal ion, is less stable than the analogous EDTA and PDTA tetraamide complexes [CuL1]2+, which contain two tertiary nitrogen and four amide oxygen atoms, due to ring size and charge effects. With increasing pH, [CuLH4]6+ undergoes deprotonation of two coordinated amide groups to give [CuLH2]4+ with a concomitant change from O-amide to N-amidate coordination. Surprisingly and in contrast to the tetraamide complexes [CuL1]2+, these two deprotonation steps could not be separated. As expected the nickel(II) complexes are less stable than their copper(II) analogues. The tetra-N-methylamides of EDTA, L1(b), and PDTA form mononuclear and binuclear complexes with Hg(II). In the case of L1(b) these have stoichiometries HgL1(b)Cl2, [HgL1(b)H−2Cl2]2−, [Hg2L1(b)Cl2]2+, Hg2L1(b)H−2Cl2 and [Hg2L1(b)H−5Cl2]3−. Based on 1H NMR and pH-metric data the proposed structure for HgL1(b)Cl2, the main tetraamide ligand containing species in the pH range <3-6.5, contains L1(b) coordinated to the metal ion through the two tertiary nitrogens and two amide oxygens while the structure of [HgL1(b)H−2Cl2]2−, the main tetraamide ligand species at pH 7.5-9.0, contains the ligand similarly coordinated but through two amidate nitrogen atoms instead of amide oxygens. The proposed structure of [Hg2L1(b)Cl2]2+, a minor species at pH 3-6.5, also based on 1H NMR and pH-metric data, contains each Hg(II) coordinated to a tertiary amino nitrogen, two amide oxygens and a chloride ligand while that of [Hg2L1(b)H−5Cl2]3−, contains each Hg(II) coordinated to a tertiary amino nitrogen, two amidate nitrogens, a chloride and a hydroxo ligand in the case of one of the Hg(II) ions. The parent EDTA and PDTA amides only form mononuclear complexes. PAMAM also forms dinuclear as well as mononuclear complexes with mercury(II) and silver(I). In the pH range 3-11 six complexes with Hg(II) i.e. [HgLH4Cl2]4+, [HgLH3Cl2]3+, [Hg2LCl2]2+, [Hg2LH−1Cl2]+, [HgLH−1Cl2]− and [HgLH−2Cl2]2− were identified and only two with Ag(I), [AgLH3]4+ and [Ag2L]2+. Based on stoichiometries, stability constant comparisons and 1H NMR data, structures are proposed for these species. Hence [HgLH4Cl2]4+ is proposed to have a similar structure to [CuLH4]6+ while [Hg2LCl2]2+has a similar structure to [Hg2L1(b)H−5Cl2]3−. 相似文献
5.
Cytidine (cyt) and adenosine (ado) react with cis-[L2Pt(μ-OH)]2(NO3)2 (L = PMe3, PPh3) in various solvents to give the nucleoside complexes cis-[L2Pt{cyt(− H),N3N4}]3(NO3)3 (L = PMe3, 1),cis-[L2Pt{cyt(− H),N4}(cyt,N3)]NO3 (L = PPh3, 2), cis-[L2Pt{ado(− H),N1N6}]2(NO3)2 (L = PMe3, 3) and cis-[L2Pt{ado(− H),N6N7}]NO3 (L = PPh3, 4). When the condensation reaction is carried out in solution of nitriles (RCN, R = Me, Ph) the amidine derivatives cis-[(PPh3)2PtNH=C(R){cyt(− 2H)}]NO3 (R = Me, 5a; R = Ph, 5b) and cis-[(PPh3)2PtNH=C(R){ado(− 2H)}]NO3 (R = Me, 6a: R = Ph, 6b) are quantitatively formed. The coordination mode of these nucleosides, characterized in solution by multinuclear NMR spectroscopy and mass spectrometry, is similar to that previously observed for the nucleobases 1-methylcytosine (1-MeCy) and 9-methyladenine (9-MeAd). The cytotoxic properties of the new complexes, and those of the nucleobase analogs, cis-[(PPh3)2PtNH=C(R){1-MeCy(− 2H)}]NO3 (R = Me, 7a: R = Ph, 7b), cis-[(PPh3)2PtNH=C(R){9-MeAd(− 2H)}]NO3 (R = Me, 8a: R = Ph, 8b) have been investigated in a wide panel of human cancer cells. Interestingly, whereas the Pt(II) nucleoside complexes (1-4) did not show appreciable cytotoxicity, the corresponding amidine derivatives (7a, 7b, 8a, 8b, 5b, and 6b) exhibited a significant in vitro antitumor activity. 相似文献
6.
Tobias Rüffer Björn Bräuer Bernhard Walfort Annie K. Powell Lorenzo Sorace 《Inorganica chimica acta》2007,360(12):3777-3784
The new mononuclear bis(oxamato) complex [n-Bu4N]2[Cu(obbo)] (1) (obbo=o-benzyl-bis(oxamato)) has been synthesized as a precursor for trinuclear oxamato-bridged transition metal complexes. Starting from 1 the homotrinuclear complexes [Cu3(obbo)(pmdta)2(NO3)](NO3)·CH2Cl2·H2O (2) and [Cu3(obbo)(tmeda)2(NO3)2(dmf)] (3) have been prepared, where pmdta = N,N,N′,N″,N″-pentamethyldiethylenetriamine, tmeda = N,N,N′,N′-tetramethylethylenediamine and dmf = dimethylformamide. The crystal structures of 1-3 were solved. The magnetic properties of 2 and 3 were studied by susceptibility measurements versus temperature. For the intramolecular J parameter values of −111 cm−1 (2) and −363 cm−1 (3) were obtained. 相似文献
7.
Palladium(II) and platinum(II) complexes with N-alkylpyridylpyrazole-derived ligands, 2-(1-ethyl-5-phenyl-1H-pyrazol-3-yl)pyridine (L1) and 2-(1-octyl-5-phenyl-1H-pyrazol-3-yl)pyridine (L2), cis-[MCl2(L)] (M = Pd(II), Pt(II)), have been synthesised. Treatment of [PdCl2(L)] (L = L1, L2) with excess of ligand (L1, L2), pyridine (py) or triphenylphosphine (PPh3) in the presence of AgBF4 and NaBPh4 produced the following complexes: [Pd(L)2](BPh4)2, [Pd(L)(py)2](BPh4)2 and [Pd(L)(PPh3)2](BPh4)2. All complexes have been characterised by elemental analyses, conductivity, IR and NMR spectroscopies. The crystal structures of cis-[PdCl2(L2)] (2) and cis-[PtCl2(L1)] (3) were determined by a single crystal X-ray diffraction method. In both complexes, the metal atom is coordinated by one pyrazole nitrogen, one pyridine nitrogen and two chlorine atoms in a distorted square-planar geometry. In complex 3, π-π stacking between pairs of molecules is observed. 相似文献
8.
Zala Mahendrasinh Sujit B. Kumar Albert Escuer E. Suresh 《Inorganica chimica acta》2011,375(1):333-337
Binuclear cyanate bridged nickel(II) complex [Ni(L)(NCO)]2(PF6)2 (1) and copper(II) complex [Cu(L)(NCO)]2(PF6)2 (2), where L is N,N-bis(3,5-dimethylpyrazol-1-ylmethyl)aminomethylpyridine, a tetradentate N4-coordinated ligand have been synthesized and characterized by physicochemical method. The structures of complexes 1 and 2 have been studied by single crystal X-ray diffraction analysis. The structure analysis reveals that both nickel(II) and copper(II) center are coordinated in distorted octahedral fashion and coordination mode of cyanate ligand is end-to-end (μ-1,3) for complex 1 but it is double end-on (μ-1,1) mode for complex 2. The variable temperature magnetic susceptibility data, measured from 2 to 300 K, show weak antiferromagnetic interaction with J value −6.2(1) cm−1 for complex 1, whereas complex 2 has very weak ferromagnetic interaction with J value +0.5(1) cm−1. 相似文献
9.
Three Cu(II)-azido complexes of formula [Cu2L2(N3)2] (1), [Cu2L2(N3)2]·H2O (2) and [CuL(N3)]n (3) have been synthesized using the same tridentate Schiff base ligand HL (2-[(3-methylaminopropylimino)-methyl]-phenol), the condensation product of N-methyl-1,3-propanediamine and salicyldehyde). Compounds 1 and 2 are basal-apical μ-1,1 double azido bridged dimers. The dimeric structure of 1 is centrosymmetric but that of 2 is non-centrommetric. Compound 3 is a μ-1,1 single azido bridged 1D chain. The three complexes interconvert in solution and can be obtained in pure form by carefully controlling the synthetic conditions. Compound 2 undergoes an irreversible transformation to 1 upon dehydration in the solid state. The magnetic properties of compounds 1 and 2 show the presence of weak antiferromagnetic exchange interactions mediated by the double 1,1-N3 azido bridges (J = −2.59(4) and −0.10(1) cm−1, respectively). The single 1,1-N3 bridge in compound 3 mediates a negligible exchange interaction. 相似文献
10.
Palladium [PdCl2(L)] complexes with N-alkylpyridylpyrazole derived ligands [2-(5-trifluoromethyl-1H-pyrazol-3-yl)pyridine (L1), 2-(1-ethyl-5-trifluoromethyl-1H-pyrazol-3-yl)pyridine (L2), 2-(1-octyl-5-trifluoromethyl-1H-pyrazol-3-yl)pyridine (L3), and 2-(3-pyridin-2-yl-5-trifluoromethyl-pyrazol-1-yl)ethanol (L4) were synthesised. The crystal and molecular structures of [PdCl2(L)] (L = L2, L3, L4) were resolved by X-ray diffraction, and consist of monomeric cis-[PdCl2(L)] molecules. The palladium centre has a typical square-planar geometry, with a slight tetrahedral distortion. The tetra-coordinate metal atom is bonded to one pyridinic nitrogen, one pyrazolic nitrogen and two chlorine ligands in cis disposition. Reaction of L (L2, L4) with [Pd(CH3CN)4](BF4)2, in the ratio 1M:2L, gave complexes [Pd(L)]2(BF4)2. Treatment of [PdCl2(L)] (L = L2, L4) with NaBF4 and pyridine (py) and treatment of the same complexes with AgBF4 and triphenylphosphine (PPh3) yielded [Pd(L)(py)2](BF4)2 and [Pd(L)(PPh3)2](BF4)2 complexes, respectively. Finally, reaction of [PdCl2(L4)] with 1 equiv of AgBF4 yields [PdCl(L4)](BF4). 相似文献
11.
Two novel Co(II) coordination polymers {[Co(H2O)2(CH3OH)2(4-bpfp)](NO3)2}n1 (4-bpfp=N,N′-bis(4-pyridylformyl)piperazine) and [Co(NCS)2(CH3OH)2(3-bpfp)]n2 (3-bpfp=N,N′-bis(3-pyridylformyl)piperazine) have been synthesized and characterized by single crystal X-ray diffraction. Both the polymers consist of one-dimensional chains constructed by bridging bpfp ligands and Co(II) ions. The existence of O?H-O hydrogen bond in 1 and S?H-O hydrogen bond in 2 play important roles in creating interesting supramolecular structures. Their third-order nonlinear optical (NLO) properties in DMF solution have been studied by Z-scan technique. The results reveal that polymers 1 and 2 exhibit strong NLO absorption effects (α2=9.00×10−11 m W−1 for 1; 1.41 × 10−10 m W−1 for 2) and self-focusing performance (n2=3.24×10−16 esu for 1; 3.05 × 10−16 esu for 2) in DMF solutions. The corresponding effective NLO susceptibilities χ(3) values are 3.08 × 10−12 esu (1) and 4.70 × 10−12 esu (2). All of the values are comparable to those of the reported good NLO materials. Additionally, the TG-DTA results of the two polymers are in agreement with the crystal structures. 相似文献
12.
Dipankar Maity W.S. Sheldrick Bilwadal Bandyopadhyay 《Inorganica chimica acta》2006,359(10):3197-3204
Synthesis and single crystal X-ray structures of H2L1 and VO(L1)(HL) [H2L1 = N,N-bis(2-hydroxy-3,5-ditertiarybutyl)-N′,N′-dimethylethylendiamine) or simply aminebis(phenol) and H2L = salicylic acid) are reported here. The complex [VO(L1)(HL)] is in distorted octahedral geometry under O4N2 donor environment where the basal core is defined by O(1), O(3), O(2) and N(5) atoms and two axial coordinates are occupied by O(4), an alkoxo-group and N(1), an imino-nitrogen atom. The electron spray mass spectrometric study on [VO(L1)(HL)] in MeCN clearly points out the existence of single species in solution. Again, the 51V NMR of the bulk polycrystalline sample reveals that the complex [VO(L1)(HL)] mainly exists in three out of four possible isomers. The formation of [VO(L1)(HL)] from both [VO(L1)(OMe)] and [VO(L1)(OEt)] was followed kinetically by reacting with salicylic acid in MeCN. The presence of isosbestic point indicates a clean conversion of the reactants to product. 相似文献
13.
Four new zinc(II) cyclams of the composition {Zn(L)(tp2−) · H2O}n (1), {Zn(L)(H2bta2−) · 2H2O}n (2), [Zn2(L)2(ox2−)] 2ClO4 · 2DMF (3), and Zn(L)(H2btc−)2 · 2DMF (4), where L = cyclam, tp2− = 1,4-benzenedicarboxylate ion, H2bta2− = 1,2,4,5-benzenetetracarboxylate ion, ox2− = oxalate ion, DMF = N,N-dimethylformamide, and H2btc− = 1,3,5-benzenetricarboxylate ion, have been synthesized and structurally characterized by a combination of analytical, spectroscopic and crystallographic methods. The carboxylato ligands in the complexes 1-4 show strong coordination tendencies toward zinc(II) cyclams with hydrogen bonding interactions between the pre-organized N-H groups of the macrocycle and oxygen atoms of the carboxylato ligands. The macrocycles in 1, 2, and 4 adopt trans-III configurations with the appropriate R,R,S,S arrangement of the four chiral nitrogen centers, respectively. However, the complex 3 shows an unusual cis V conformation with the R,R,R,R nitrogen configuration. The finding of strong interactions between the carboxylato ligands and the zinc(II) ions may provide additional knowledge for the improved design of receptor-targeted zinc(II) cyclams in anti-HIV agents. 相似文献
14.
Laura Battan Mario Manassero Alessandro Pasini Mirella Sansoni 《Inorganica chimica acta》2005,358(3):555-564
The interaction of an excess of the title ligands L− with the cis-Pt(phos)2 moieties gives compounds a-bcis-[Pt(L-O)2(phos)2] (a, phos = P(Ph)3; b, phos = 1/2 dppe), in which O- is preferred to S-coordination. Such preference is confirmed by the fact that the same products are obtained by reaction of excess of L− with the previously reported a-d complexes [Pt(L-O,S)(phos)2]+, (c, phos = PPh3, d, phos = 1/2 dppe), for which chelate ring opening occurs with rupture of Pt-S rather than Pt-O bonds. Compound a can be obtained also by oxidative addition of HL to [Pt(PPh3)3]. The Pt-O bonds in compounds a-d are stable towards substitution by Me2SO, pyridine and tetramethylthiourea. Substitution of L’s occurs with N,N′-diethyldithiocarbamate, which forms a very stable chelate with Pt(II). Thiourea and N,N′-dimethylthiourea also react, because they give rise to cyclometallated products [Pt(phos)2(NRC(S)NHR)]+ (R = H, CH3), with one ionised thioamido group, as revealed by an X-ray investigation of [Pt(PPh3)2(NHC(S)NH2)]+. The preference of O versus S coordination, as well as the stability of the Pt-O bonds, are discussed in terms of antisymbiosis. 相似文献
15.
I. Ravikumar 《Inorganica chimica acta》2010,363(12):2886-520
Syntheses and crystal structures of tren-based amide, L1, N,N′,N″-tris[(2-amino-ethyl)-4-nitro-benzamide] and L2, N,N′,N″-tris[(2-amino-ethyl)-2-nitro-benzamide] are reported and compared with previously published tripodal amide receptor L3, N,N′,N″-tris[(2-amino-ethyl)-3-nitro-benzamide]. The crystallographic results show intramolecular and intermolecular hydrogen-bonding interactions between two arms of the tripodal receptor and two other adjacent molecules in cases of L1 and L2 whereas in addition to the above interactions an aromatic π···π stacking among tripodal arms is also observed in L3. Receptors L1, L2 and L3 having electron withdrawing -NO2 substituted (para, ortho and meta, respectively) phenyl moieties are explored toward their solution state anion binding properties and selectivity studies. The substantial changes in chemical shifts are observed for the amide protons (-NH) and aromatic protons (-CH) with F− and Cl− in cases of L1 and L3, and only with F− for L2, indicating the participation of -NH and -CH protons in the solution state binding events. Binding constants for the above cases are calculated by 1H NMR titration upon monitoring the -NH signal. Receptor L2 shows exclusive selectivity toward F− in dimethyl sulfoxide (DMSO). The structural aspects of binding I−, ClO4− and SiF62− with the monoprotonated L1, L1H+·I−·DMF (1), L1H+·ClO4−·DMF (2) and L1H+·0.5SiF62−·H2O (3), respectively are examined crystallographically. Anion binding with multiple receptor units is observed via amide N-H···anion as well as aryl C-H···anion hydrogen-bonding interactions in all the complexes as observed in cases of previously reported crystal structures of anionic complexes of protonated L3. The aryl group having nitro functionality that contributes to solution state anion binding with the neutral receptor and solid state coordination in complexes 1-3 through CH···anion interactions is noteworthy. 相似文献
16.
Katerina N. Lazarou 《Inorganica chimica acta》2011,370(1):50-58
The reactions of salicylaldehyde oxime (H2salox) with CuII precursors yielded the known complexes [Cu(Hsalox)2] (1) and [Cu(Hsalox)2]n (2), as well as complexes [Cu3(salox)(L1)(L2)]·MeCN (3·MeCN), [CuCl(L1)] (4) and [Cu2Na(O2CMe)5(HO2CMe)]n (5), where L1− = o-O-C6H4-CHNO-C(CH3)NH and L23− = o-O-C6H4-CHNO-C(o-O-C6H4)N. L1− was formed in situ via the nucleophilic addition of the oximato O-atom of salox2− to the unsaturated nitrile group of the MeCN reaction solvent. L23− is also formed in situ probably through the nucleophilic attack of the oximato O-atom to the unsaturated nitrile group of salicylnitrile; the latter, although not directly added to the reaction mixture, can be produced via the dehydration of salox2−. Compounds 1 and 2 contain Hsalox− bound to the metal center in two different coordination modes; they both contain the same mononuclear unit, however a 2D network is generated in 2 due to a relatively long Cu-Ooximato bond. Compound 3 contains three different ligands, i.e. salox2−, L1− and L23−, which act as μ3-κ2O:κO′:κN, κO:κN:κN′ and μ3-κ2O:κ2N:κO′:κN′, respectively, whereas 4 consists of a square planar CuII atom bound to a κO:κN:κN′ L1− and a chloride ion. Compound 5 consists of dinuclear [Cu2(O2CMe)5(HO2CMe)]− units and Na+ ions assembled into an overall 3D network structure. Magnetic susceptibility measurements from polycrystalline samples of 2 and 5 gave best-fit parameters J = +0.36 cm−1 (H = −J?i?j) and J = −360 cm−1, zj = +20 cm−1 (H = −J?i?j − zJ〈Sz〉?z), respectively. 相似文献
17.
N,N′-bis[4-(2-aminoethyl)morpholino]glyoxime (H2L) (Fig. 1), has been prepared in various yields using three different methods. The most efficient of these methods is the technique of microwave irradiation. The crystal structures of H2L, and of two nickel(II) complexes 1 and 2 have been determined by single crystal X-ray diffraction. Both nickel(II) complexes have a metal-ligand ratio of 1:2 in which the ligand coordinates through the two nitrogen atoms as do most vic-dioximes. The nickel(II) complexes are either hydrogen (1) or boron diphenyl bridged (2). Complex 1 was synthesized by reacting H2L with nickel(II) chloride in refluxing ethanol. Complex 2 was prepared at room temperature in an ethanol solution containing excess NaBPh4. Elemental analyses, NMR(1H, 13C), IR and mass data are also presented. 相似文献
18.
Yongshu Xie Hui Jiang Albert Sun-Chi ChanQingliang Liu Xiaolong XuChenxia Du Yu Zhu 《Inorganica chimica acta》2002,333(1):138-143
Two copper(II) complexes [Cu4(L1)4] (1) and [Cu2(phen)2(HL2)2] (ClO4)2 (2) have been synthesized from two potentially tridentate ligands N-(2-hydroxybenzyl) propanolamine (H2L1) and N-(2-hydroxybenzyl) ethanolamine (H2L2). X-ray analyses revealed that 1 contains a Cu4O4 cubane core, with each two Cu(II) atoms bridged by a pair of alkoxides; 2 has a bis(μ2-phenoxo)-bridged dicopper(II) structure. Variable temperature magnetic measurements of 1 have revealed that the correlation between 2J and the bridge angles φ for 1 shows a very strong antiferromagnetic tendency, i.e. the ferromagnetic and antiferromagnetic interactions cross at the φ of 94.5°. The relatively weak antiferromagnetic interactions (2J=−226.8 cm−1) with respect to the bridge angles (φ=100.4°) for 2 have been ascribed to the pyramidal distortions at the phenoxide oxygen atoms in addition to the unfavorable overlaps of the magnetic orbitals for the highly distorted copper coordination polyhedra. 相似文献
19.
Rojalin Sahu 《Inorganica chimica acta》2010,363(14):4008-4016
Four new hetero-bimetallic Co3+-Na+ and Co3+-K+ coordination polymers having the molecular formulae [Na(H2O)Co(L)(N3)3]n (1), [Na2Co(L)(N3)3(H2O)5][Co(L)(N3)3] (2), K[Co(L)(NCS)3]·H2O (3) and K[Co(L)2][Co(NCS)4]·0.5H2O (4), were synthesized. Compounds 1-4 were characterized by single crystal X-ray diffraction, IR, UV-Vis, and thermogravimetric methods. These bimetallic systems have EE, EO azide bridge (1, 2) as well as bent (1, 2, 3) and linear (1, 4) aquo bridges. Important features observed among them were: a Z-shaped and diamond-shaped Co2Na2 clusters in 1, a centrosymmetric double ladder like polymer based on Na4 cluster in 2, and a linear KOK core having paddle-wheel structure in 4. 相似文献
20.
Anuj Kumar Sharma 《Inorganica chimica acta》2011,372(1):327-332
Using a non-planar tridentate ligand 2,6-bis(pyrazol-1-ylmethyl)pyridine (L5) two new coordination complexes [(L5)CoII(H2O)3]Cl2 (1) and [(L5)NiII(H2O)2Cl]Cl·H2O (2) have been synthesized and structurally characterized. Complex 1 has N3O3 distorted octahedral environment around CoII with coordination by L5 (two pyrazole and a pyridine nitrogen in a facial mode) and three water molecules. Complex 2 has N3O2Cl distorted octahedral geometry around NiII with meridional L5 coordination, two water molecules, and a Cl− ion. Analysis of the crystal packing diagram reveals the involvement of solvent (water as metal-coordinated and as solvent of crystallization) and counteranion (Cl−) to play significant roles in generating 1D chains, involving O-H···Cl, and O-H···O interactions. 相似文献