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1.
[N,N′-bis(2′-pyridinecarboxamido)-1,3-propane] - nickel(II) monohydrate, C15H16N4O3Ni is monoclinic, space group P21/c, with a = 7.174(4), b = 18.590(3), c = 11.641(5) Å, β = 110.69(2)°, Z = 4. The structure was refined to R = 0.030 for 1826 diffractometer data using full-matrix least-squares methods. The N4-ligand coordinates to the nickel atom in an irregular square plane [average Ni-Namide 1.864(4), Ni-Npyridine 1.912(3) Å and Namide-Ni-Namide 96.0(1), Npyridine-Ni-Npyridine 98.7(1)°] with a tetrahedral twist of 15.9° at the nickel atom. The two picolinamide units are related by an approximate two-fold axis and the enforced strain in the molecule results in significant non-planar distortions in the amide chelate rings and the pyridyl rings. The plane of the chelate molecule lies approximately perpendicular to [100] and the lattice water molecule hydrogen bonds amide oxygen atoms to form chains parallel to [101] 相似文献
2.
Yvonne Arendt 《Carbohydrate research》2009,344(10):1213-8523
The [PdII{(R,R)-chxn}(OH)2] reagent (chxn = 1,2-diaminocyclohexane) is introduced as a metal probe for the detection of the bidentate chelating sites of a glycose. Two moles of hydroxide per mole palladium support double deprotonation of potentially chelating diol functions at a glycose’s backbone. The individual chelating sites are detected using one- and two-dimensional NMR techniques. At equimolar amounts of palladium(II) and aldose, the metal-binding sites include mostly the hydroxy function at the anomeric carbon atom. Chelators are derived from both the pyranose and the furanose isomers. Most pyranose-based chelators form five-membered chelate rings by using their 1,2-diol function. Though 1,2-diolate bonding is also common to the furanoses, the formation of six-membered chelate rings by 1,3-bonding is more significant for them. Metal-excess conditions provoke mostly bis-bidentate 1,2;3,4-chelation but unusual isomers form also: thus d-xylose is dimetallated in its all-axial β-pyranose form, and erythrose’s dimetallation results in the formation of two isomers of a metal derivative of the open-chain hydrate. The spectroscopic results are supported by crystal-structure determinations on [Pd{(R,R)-chxn}(α-d-Xylp1,2H−2-κO1,2)]·H2O (Xyl = xylose), [Pd{(R,R)-chxn}(α-d-Ribp1,2H−2-κO1,2)]·2.25H2O (Rib = ribose), [Pd{(R,R)-chxn}(α-l-Thrf1,3H−2-κO1,3)]·2H2O (Thr = threose) and [Pd{(R,R)-chxn}(α-d-Eryf1,3H−2-κO1,3)]·3H2O (Ery = erythrose). 相似文献
3.
The metal ion coordinating properties of the ligands N,N-bis(2-methylquinoline)-2-(2-aminoethyl)pyridine (DQPEA) and N,N-bis(2-methylquinoline)-2-(2-aminomethyl)pyridine (DQPMA) are presented. DQPEA and DQPMA differ only in that DQPEA forms six-membered chelate rings that involve the pyridyl group, whereas DQPMA forms analogous five-membered chelate rings.These two ligands illustrate the application of a ligand design principle, which states that increase of chelate ring size in a ligand will result in increase in selectivity for smaller relative to larger metal ions. The formation constants (log K1) of DQPEA and DQPMA with Ni(II), Cu(II), Zn(II), Cd(II) and Pb(II) are reported. As expected from the applied ligand design principle, small metal ions such as Ni(II) and Zn(II) show increases in log K1 with DQPEA (six-membered chelate ring) relative to DQPMA (five-membered chelate ring), while large metal ions such as Cd(II) and Pb(II) show decreases in log K1 when the chelate ring increases in size. In order to further understand the steric origin of the destabilization of complexes of metal ions of differing sizes by the six-membered chelate ring of DQPEA, the structures of [Zn(DQPEA)H2O](ClO4)2 (1) [triclinic, , a = 9.2906(10), b = 10.3943(10), c = 17.3880(18) Å, α = 82.748(7)°, β = 88.519(7)°, γ = 66.957(6)°, Z = 4, R = 0.073] and [Cd(DQPEA)(NO3)2] (2) [monoclinic, C2/c, a = 22.160(3), b = 15.9444(18), c = 16.6962(18) Å, β = 119.780(3)°, Z = 8, R = 0.0425] are reported. The Zn in (1) is five-coordinate, with a water molecule completing the coordination sphere. The Cd(II) in (2) is six-coordinate, with two unidentate nitrates coordinated to the Cd. It is found that the bonds to the quinaldine nitrogens in the DQPEA complexes are considerably stretched as compared to those of analogous TPyA (tri(pyridylmethyl)amine) complexes, which effect is attributed to the greater steric crowding in the DQPEA complexes. The structures are analyzed for indications of the origins of the destabilization of the complex of the large Cd(II) ion relative to the smaller Zn(II) ion. A possible cause is the greater distortion of the six-membered chelate ring in (2) than in (1), as evidenced by torsion angles that are further away from the ideal values in (2) than in (1). Fluorescence properties of the DQPMA and DQPEA complexes of Zn(II) and Cd(II) are reported. It is found that the DQPEA complex of Zn(II) has increased fluorescence intensity compared to the DQPMA complex, while for the Cd(II) complex the opposite is found. This is related to the greater strain in the six-membered chelate ring of the Cd(II) DQPEA complex as compared to the Zn(II) complex, with resulting poorer overlap in the Cd-N bond, and hence greater ability to quench the fluorescence in the Cd(II) complex. 相似文献
4.
Takeshi Fujinami Ryoko Kitashima Naohide Matsumoto Seiichiro Iijima 《Inorganica chimica acta》2011,376(1):136-143
Two binuclear iron(III) complexes, [L1FeIII(bpy)FeIIIL1](BPh4)2 (1) and [L2FeIII(bpy)FeIIIL2](BPh4)2 (2), were synthesized and characterized, where H2L1 and H2L2 denote bis(salicylicdeneaminopropyl)methylamine and bis(3-methoxysalicylideneaminopropyl)methylamine, respectively, and bpy denotes 4,4′-bipyridine and BPh4− denotes tetraphenylborate. Complexes 1 and 2 consist of one and two crystallographically unique Fe sites, respectively, while they have a similar binuclear complex-cation [LnFeIII(bpy)FeIIILn]2+ (n = 1, 2) bridged by 4,4′-bipyridine and two tetraphenylborate ions as the counter anions. The magnetic susceptibility measurements of 1 and 2 showed one-step and two-step spin crossover (SCO), respectively. The four saturated six-membered chelate rings at the aminopropyl moieties of 1 exhibit disorder throughout one-step SCO. The two chelate rings of one Fe site of 2 exhibit disorder but the other two of another Fe site do not. The different SCO behaviors of 1 and 2 were ascribed to one and two crystallographically unique Fe sites and the order/disorder at the saturated six-membered chelate rings of aminopropyl moieties. 相似文献
5.
Igor O. Fritsky Jolanta ?wi?tek-Koz?owska Agnieszka Dobosz Nikolay M. Dudarenko 《Inorganica chimica acta》2004,357(12):3746-3752
The formation of the molecular assemblies consisting of anionic and cationic molecules may lead to their interesting structural properties. In this work, we present three new structures based on the tetradentate oxime and amide open-chain ligand CH3-C(NOH)-C(O)-NH-(CH2)3-NH-C(O)-C(NOH)-CH3 (PAP). All the structures contain the complex cations, complex anions [M(PAP-3H)]− and solvating water molecules. These are H-bonded complex anions: [Ni(1,3-pn)2(H2O)2][Ni(PAP-3H)]2 · 4 H2O (1), [Ni(Im)4(H2O)2][Ni(PAP-3H)]2 (2) and [Cu(Im)4(H2O)2][Cu(PAP-3H)]2 · 2H2O (3) (Im=imidazole; 1-3-pn=1,3-diaminopropane). All compounds were synthesised by co-crystallisation of octahedral amine-containing cationic complex with oxime-containing anionic complexes in methanol solution. They were compared with some earlier reported assemblies based on the same ligand (PAP). The comparison of the structures reveals one distinct difference in the separation between the cis-situated oximate oxygen atoms O(1)?O(4) in the copper complexes. The consequence of this effect is the lengthening of the Cu-N distances. In the nickel complexes containing [Ni(PAP-3H)]− anion this effect is much less pronounced. 相似文献
6.
α-Aqua[N,N′-bis(2′-pyridinecarboxamido)-1,3-propane]copper(II) dihydrate, C15H20N4O5Cu, is monoclinic, space group P21/c, with a = 11.719(2), b = 13.092(2), c = 12.663(2) Å, β = 119.56(1)°, Z = 4. The structure was refined to R = 0.026 for 2398 diffractometer data using full-matrix least-squares methods. The copper atom is five-coordinate with the N4-tetradentate ligand encompassing the base of a distorted square-based pyramid which is appreciably distorted towards a trigonal bipyramid [average Cu-N(amide) 1.950(2), Cu-N(pyridine) 2.043(2) Å, N(amide)-Cu-N(amide) 94.5(1), N(pyridine)-Cu-N(pyridine) 100.2(1)°] and with the copper atom lying 0.27 Å above the N4 plane towards the apical water molecule [Cu-O 2.236(2) Å]. The central six-membered chelate ring adopts a skewed boat conformation and the enforced strain in the molecule results in non-planar distortions in the pyridine rings with only small distortions in the amide groups. The molecules pack in sheets parallel to (10) and the hydrogen-bonding network involves the water molecules and the amide oxygen atoms of the ligand. 相似文献
7.
Two new linear and V-shaped tetradentate ligands, namely 1,4-bis(2-hexahydropyrimidyl)benzene (L) and 1,3-bis(2-hexahydropyrimidyl)benzene (L′), and their silver(I) complexes, [Ag2L(μ-ONO2)](NO3) · 2H2O (1), [Ag2L(μ-pn)](NO3)2 (2), [Ag2L(μ-pn)](ClO4)2 (3) and [Ag4L′2(H2O)](NO3)4 · 5H2O (4) (pn=1,3-diaminopropane) have been synthesized in situ and structurally characterized by single-crystal X-ray diffraction. 1 and 2 were obtained from the same reaction solution but different crystallization conditions. 1 is an one-dimensional chain featuring cuboid tetranuclear silver(I) units interconnected through monoatomic nitrate bridges. Both 2 and 3 are ribbon-like helical compounds in which each L ligand acts in a tetradentate bridging mode to interconnect four metal atoms, and each pn ligand functions in a bidentate bridging mode to link a pair of metal atoms. 4 shows a truncated square-pyramidal tetranuclear motif arose by the V-shaped L′ ligand. Close Ag?Ag separations (2.901-2.939 Å) assisted by bis(hexahydropyrimidine) bridges were observed in 1 and 4, indicating metal-metal interactions. Photoluminescence of 1-4 has also been observed in the solid state and solution at room temperature and low temperature, respectively. 相似文献
8.
Adele Cerquetella Claudio Pettinari Riccardo Pettinari Brian W. Skelton 《Inorganica chimica acta》2007,360(7):2265-2270
Six new adducts of the form AgX:PPh3:H2C(pzx)2 (1:1:1) (H2C(pzx)2 = H2C(pz)2 = bis(pyrazolyl)methane or H2C(pzMe2)2 = bis(3,5-dimethylpyrazolyl)methane; X = ClO4, NO3, SO3CF3) have been synthesized and characterized by analytical, spectroscopic (IR, far-IR, 1H and 31P NMR) and two of them also by single crystal X-ray diffraction studies for comparison with counterpart adducts with 2,2′-bipyridyl (‘bpy’) derivatives reported in a previous paper, the bpy-derived ligands forming five-membered chelate rings, while the present H2C(pzx)2 should, potentially, form six-membered rings. Such is the case, the two adducts exhibiting quasi-planar N2AgP coordination environments, perturbed by the approach of the oxyanion, unidentate in the case of the perchlorate but, in the case of the nitrate, an interesting disordered aggregate of differing unidentate modes. 相似文献
9.
1,3-Diphenyl-1,3-propandionatobis(triphenylantimony)diphenylrhodium(III)dibenzene, [Rh(DPD)(SbPh3)2Ph2]·2(C6H6) has been isolated as the product of the reaction between the Rh(I) complex 1,3-diphenyl-1,3-propandionatodicarbonylrhodium(I), [Rh(DPD)(CO)2], and triphenylantimony in acetone and in n-hexane medium. The crystal and molecular structure was determined from single crystal X-ray diffractometer data. The unit cell is triclinic with a = 19.083, b = 13.167, c = 13.536 Å, α = 81.81°, β = 111.59°, γ = 100.49°, Z = 2 and space group P. The structure was refined to a R-value of 0.079 for 6637 contributing reflections. The coordination polyhedron can be described as a slightly distorted octahedron in which the Rh-atom is coordinated by two phenyl groups, two oxygen atoms of a chelate ring, which are in cis position to one another, and two antimony-atoms of the two SbPh3 ligands, which are in trans positions. 相似文献
10.
It has been established that small molecule model complexes have been useful in studying more complex biological systems of metalloproteins. Because many metalloproteins have active sites that contain multiple histidine residues bound to a metal center, a series of imidazole-containing scorpionate ligands and the associated Co and Ni complexes have been developed to investigate the bonding parameters of histidine containing active sites. The tris(2-imidazolyl) carbinol (2-TIC, 6) and tris[2-(N-methylimidazolyl)] carbinol (2-MeTIC, 7) complexes of Ni2+ and Co2+, namely [Co(2-MeTIC)2]Cl2 (8), [Co(2-MeTIC)2](NO3)2 (9), [Ni(2-MeTIC)2]Cl2 (10), [Ni(2-MeTIC)2](NO3)2 (11), [Co(2-TIC)2](NO3)2 (12), and [Ni(2-TIC)2](NO3)2 (13), have been prepared from the reaction of the appropriate ligand and appropriate metal salt in polar solvent. These complexes have been characterized by single crystal X-ray diffraction, spectroscopic techniques, and magnetic susceptibility. In each solid-state structure the metal center in the cation coordinates to three N atoms from two ligands and adopts a pseudo-octahedral coordination geometry. The X-ray characterization of tris[2-(N-methylimidazolyl)] carbinol is also reported. 相似文献
11.
《Inorganica chimica acta》1986,113(2):157-160
2-Carboxyquinolinatobis(triphenylphosphite)rhodium (I) was prepared by means of the following reaction: [Rh(Qin)(CO)2] + 2P(OPh)3→ [Rh(Qin)(P(OPh)3)2] + 2CO It crystallizes in the triclinic space groupP] witha = 12.406,b = 18.702,c = 9.547 Å, α = 76.36, β = 111.35, γ = 97.88o and Z = 2. The structure was determined from 4520 observed reflections. the final R value was 0.051. The RhP bond distances may indicate (although the difference is only about 3σ) that the nitrogen atom the chelate ring has the largest trans influence. The chelate ring is significantly folded along the N---O axis. 相似文献
12.
Polydentate nitrogen heterocycle ligand 2,3-bis(2-pyridyl)pyrazine (2,3-dpp) reacted with M(NO3)x (M = Ag, x = 1; M = Cd, x = 2) to give two new complexes [Ag(2,3-dpp)(NO3)]2 (1) and [Cd(2,3-dpp)(NO3)2]n (2). Both complexes have been characterized by single-crystal X-ray diffraction, elemental analyses, IR and 1H NMR spectroscopy. Single-crystal X-ray analyses showed that complex 1 crystallized in monoclinic, space group P21/n is a dimmer containing penta-coordinated Ag+ ion. While compound 2 has 1D chain-like structure with repeat unit Cd(2,3-dpp)(NO3)2, in which the Cd(II) presents octa-coordinated N4O4 donor set with two four-membered chelating rings and two five-membered chelating rings around Cd(II) ion. Meanwhile, every neutral chain [Cd(2,3-dpp)(NO3)2]n is mutually connected by face-to-face π?π packing interactions to form a two dimensional layer. Furthermore, antibacterial activities of compound 1 and luminescent property of the compound 2 are also investigated. 相似文献
13.
V. B. Ivanov M. J. Bloemink P. A. Cheltsov E. I. Bystrova T. N. Fedotova J. Reedijk 《Biometals》1996,9(3):249-257
The amine substituent effect in compounds [Pt(diamine)Cl2] on inhibition of maize and cucumber root growth and branching has been investigated. The diamines used were ethylenediamine (en),N-methylethylenediamine (men),N,N-dimethylethylenediamine (N,N-dmen),N,N-dimethylethylenediamine (N,N-dmen),N,N,N,N-tetramethylethylenediamine (tmen), 1,2-propanediamine (1,2-pn), 2-methyl-1,2-propanediamine (ibn), 2,3 dimethyl-2,3-butanediamine (C-tmen), 1,3-propanediamine (1,3-pn), 2,2-dimethyl-1,3-propanediamine (C2-dm-1,3 pn),N,N-dimethyl-1,3-propanediamine (N,N-dm-1,3-pn). Increased substitution of hydrogen atoms of the amine part with CH3 groups reduces the cytostatic activity of complexes. The substitution of hydrogen atoms of NH2 and vicinal CH2 groups displays similar results. C-2 dimethylation (C-dm-1,3-pn) does not change the activity of the complex compared with (1,3-pn). It was observed that maize and cucumber roots differ in their relative sensitivity to various complexes. All complexes containing pn and their substituted analogs inhibited cucumber root growth weaker than that in maize. A comparison of obtained data with earlier published results concerning antitumor activity of complexes shows that they correlate in a similar manner with increased substitution of amino groups. Therefore, roots may be used as cheap test objects for primary screening of cytostatics. The general tendency of a decrease in cytostatic activity goes parallel with the number of Nor vicinal C-methyl groups and seems to arise from a decrease in hydrogen-bonding potential; however, some other possible reasons are also discussed. The activity discrimination by different species in our experiments and clearly different results forN,N-dimethylation depending on the chelate ring size (en and pn derivatives) on maize cannot be attributed to slower ligand-exchange kinetics from methylation. It is possible to assume that the major role in cytostatic activity of platinum complexes belongs to a cell repair system, i.e. the ability to eliminate platinum diamine fragments from DNA, depending on the number and strength of hydrogen bonds formed by thecis-diamine fragment. 相似文献
14.
The crystal structure of the nickel(II) complex (C20H22N6S2Ni) of the N2S2 ligand hexan-2,5-dionebis(4-phenyl-thiosemicarbazone) has been solved using diffractometric data. The complex, exhibiting greater antibacterial activity than the free ligand, crystallizes in the space group C2 with a = 17.414(1) Å, b = 8.485(1) Å, c = 15.129(3) Å, β = 104.09(3)°, Z = 4, d(obsd) = 1.425 g cm?3, d(calc) = 1.438 g cm?3 and μ(Mo-Kga) = 10.978 cm?1. The structure has been refined by full-matrix least squares to a final R = 0.033 and Rw = 0.041 using 1743 reflections with I ≥ 3σ(I) out of 2049 unique reflections measured (2° ≤ gq ≤ 27°). The hydrogens were either located or placed in their calculated positions. The nickel(II) ion lies in the tetrahedrally distorted square planar ligand field of the tetradentate ligand forming two five membered and one seven membered chelate rings. It is observed that the lack of conjugation in the seven membered chelate rings of the present complex and of similar complexes leads to dissymmetry in the ring geometry. The metal ion is coordinatively unsaturated and available for additional coordination in its axial directions. 相似文献
15.
Anna G. Matveeva Alexander S. Peregudov Evgenij I. Matrosov Zoya A. Starikova Sergej V. Matveev Eduard E. Nifant’ev 《Inorganica chimica acta》2009,362(10):3607-249
The solution structures of the lanthanide complexes, [Ln(L)(NO3)3] and [Ln(L)2(NO3)3], where L = bis(diphenylphosphorylmethyl)mesitylene and Ln = La, Ce, Nd, Er, were investigated by 31P NMR and IR spectroscopy, conductivity and sedimentation analysis. Variable-temperature 31P{1H} NMR spectroscopy was used to identify species present in solution and to monitor their interconversions. The results indicate that equilibrium between molecular complexes [Ln(L)n(NO3)3]0 and cationic species (as ion pairs [Ln(L)n(NO3)2]+ · (NO3)− and as free ions [Ln(L)n(NO3)2]+, throughout n = 1, 2) in solutions can be observed by 31P{1H} NMR spectroscopy due to separate detection of the molecular complexes and cationic species. The chelate coordination of the ligand and nitrate ions is retained in all complex species at ambient temperature except for [Er(L)2(NO3)3]. The crystal structure of [Nd(L)(NO3)3(MeCN)]MeCN was determined by X-ray diffraction. 相似文献
16.
《Inorganica chimica acta》1986,119(1):61-66
The title compounds, Ni(C5H14N2O)2Cl2 and Ni(C5H14N2O)2Br2, are isomorphous and crystallize in the orthorhombic space group Pnna with unit cell dimensions a = 13.182(3), b = 14.860(4), c = 8.742(2) Å, and a = 13.637(5), b = 15.009(4), c = 8.815(3) Å, respectively. The densities Dc and Dm are 1.42 and 1.425(4) g cm−3 for the chloride compound and 1.67 and 1.65(1) g cm-3 for the bromide; Z = 4. The data of both compounds were collected with an automatic four-circle diffractometer using ω-scan mode. The crystal structures were solved by direct methods, and the refinements, based upon 1388 and 1285 reflections with Fo > 6.0σ(Fo), yielded conventional R factors of 4.0 and 7.5%, respectively.The compounds are monomeric bischelates, where four nitrogen atoms and two oxygen atoms are coordinated octahedrally to a nickel(II) ion. The oxygen atoms are in cis-position to each other. The exact symmetries of the cations are C2. The ligand molecules are not deprotonated and are coordinated tridentately to the central atom. The six-membered ring of the chelate is in chair conformation and the five-membered ring in antisymmetric skew conformation. The chloride and bromide ions are weakly bonded to the structure with hydrogen bridges.The magnetic susceptibilities of the compounds were determined in the temperature range 93–303 K, and in both cases the magnetic data indicated octahedral nickel(II) coordination sphere with no interaction between the metal atoms. 相似文献
17.
《Inorganica chimica acta》1988,147(2):189-197
Complexes of the M(en)3Ag2(CN)4 (M = Ni, Zn, Cd) and M(en)2Ag2(CN)4 (M = Ni, Cu, Zn, Cd) type were prepared and identified by elemental analysis, infrared spectroscopy, measurement of magnetic susceptibility, and X-ray powder diffractometry. The crystal structures of Ni(en)3Ag2(CN)4 (I) and Zn(en)2Ag2(CN)4 (II) were determined by the method of monocrystal structure analysis. Complex I crystallizes in the space group C2/c, a = 1.2639(5), b = 1.3739(4), c = 1.2494(4) nm, β = 113.25(4)°, Dm = 1.86(1), Dc = 1.86 gcm−3 Z = 4, R = 0.0429. The crystal structure of I consists of complex cations [Ni(en)3]2+ and complex anions [Ag(CN)2]−. Complex II crystallizes in the space group I2/m, a = 0.9150(3), b = 1.3308(4), c = 0.6442(2) nm, β = 95.80(3)°, Dm = 2.14(1), Dc = 2.15 gcm−3, Z = 2, R = 0.0334. Its crystal structure consists of infinite, positively charged chains of the [-NCAgCNZn- (en)2]nn+ type and isolated [Ag(CN)2]− anions. The atoms of Ag are positioned parallely to the z axis and the AgAg distance is equal to 0.3221(2) nm. 相似文献
18.
The synthesis and crystal structures of two new copper complexes with chelating dicarboxylic acids are described. Reaction of copper(II) acetate with diacid H2L2 (HO2CC(Me)2OArOC(Me)2CO2H, Ar=1,3-substituted phenyl) gave a bischelate complex (L2)2Cu2 · 2MeOH with the normal paddlewheel structure and tilted, trans-oriented chelate rings with skewed conformations. The overall structure was reasonably well reproduced by density functional calculations on (L2)2Cu2. Treatment of the product from reaction of Cu2(OAc)4 and diacid H2L3 (Ar=1,3-substituted 2,4-dibromophenyl) with pyridine gave a six-coordinate mononuclear chelate (L3)Py2Cu · H2O in which one chelate carboxylate is monodentate, the other is unsymmetrically bidentate, and the pyridines are cis-coordinated. 相似文献
19.
Two sets of ligands, set-1 and set-2, have been prepared by mixing 1,3-diaminopentane and carbonyl compounds (2-acetylpyridine or pyridine-2-carboxaldehyde) in 1:1 and 1:2 ratios, respectively, and employed for the synthesis of complexes with Ni(II) perchlorate, Ni(II) thiocyanate and Ni(II) chloride. Ni(II) perchlorate yields the complexes having general formula [NiL2](ClO4)2(L = L1 [N3-(1-pyridin-2-yl-ethylidene)-pentane-1,3-diamine] for complex 1 or L2[N3-pyridin-2-ylmethylene-pentane-1,3-diamine] for complex 2) in which the Schiff bases are monocondensed terdentate, whereas Ni(II) thiocyanate results in the formation of tetradentate Schiff base complexes, [NiL(SCN)2] (L = L3[N,N′-bis-(1-pyridin-2-yl-ethylidine)-pentane-1,3-diamine] for complex 3 or L4 [N,N′-bis(pyridin-2-ylmethyline)-pentane-1,3-diamine] for complex 4) irrespective of the sets of ligands used. Complexes 5 {[NiL3(N3)2]} and 6 {[NiL4(N3)2]} are prepared by adding sodium azide to the methanol solution of complexes 1 and 2. Addition of Ni(II) chloride to the set-1 or set-2 ligands produces [Ni(pn)2]Cl2, 7, as the major product, where pn = 1,3-diaminopentane. Formation of the complexes has been explained by the activation of the imine bond by the counter anion and thereby favouring the hydrolysis of the Schiff base. All the complexes have been characterized by elemental analyses and spectral data. Single crystal X-ray diffraction studies confirm the structures of three representative members, 1, 4 and 7; all of them have distorted octahedral geometry around Ni(II). The bis-complex of terdentate ligands, 1, is the mer isomer, and complexes 4 and 7 possess trans geometry. 相似文献
20.
《Inorganica chimica acta》1988,148(1):101-104
The compound In[(pz)2BH2]3 (pz = 1-pyrazolyl, C3H3N2−) was prepared from In(NO3)3 and K[(pz)2-BH2] in water, and characterised by spectroscopic and X-ray methods. Crystals are orthorhombic,Pna21,a = 20.279(4),b = 8.884(2),c = 13.411(2)Å;R = 0.0285. Individual molecules contain a near-regular six-coordinate indium atom with In–N (av.) 2.241(5)Å. The pyrazolyl borate ligands are puckered, with dihedral angles between the two rings of each ligand in the range 133–144°. 相似文献