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1.
A nickel(II) complex with 6-(p-chlorobenzoyl)-5,7,12,14-tetramethyl-benzo[b]-1,4,8,11- tetraazacyclo[14]tetradecine was synthesized and characterized by measurements of NMR, IR and an electronic spectra. The X-ray crystal structure shows that the coordination geometry around the Ni atom is a square planar with the unsymmetrical tetraaza[14]annulene.  相似文献   

2.
This work reports a systematic investigation to understand the structural, spectroscopic and redox properties of Ni(II) ion in a set of 13-membered amide-based macrocyclic ligands. Four macrocyclic ligands containing e-donating/withdrawing substituents and their Ni(II) complexes have been synthesized and characterized. Structural analysis shows that the macrocyclic ligands create a square-planar environment and nicely accommodate the Ni(II) ion. Electrochemical results suggest that the complexes are capable of undergoing metal-centered oxidation. The electron-donating substituents on ligand lowers the redox potentials and better stabilizes the +3 oxidation state of metal. The electrochemically generated NiIII species are shown to have rich spectroscopic features. For majority of complexes, the oxidized species are concluded to be NiIII by their anisotropic EPR spectra typical for NiIII ion in square-planar geometry. The absorption and EPR spectra for nickel complex bearing an -OMe group on the ligand; however, suggest a Ni(II) complex with a ligand-based radical.  相似文献   

3.
A series of cationic nickel complexes [(η3-methally)Ni(PP(O))]SbF6 (1–4) [PP(O) = Ph2P(CH2)P(O)Ph2 (dppmO) (1), Ph2P(CH2)2P(O)Ph2 (dppeO) (2), Ph2P(CH2)3P(O)Ph2 (dpppO) (3), pTol2P(CH2)P(O)pTol2 (dtolpmO) (4)] has been synthesized in good yields by treatment of [(η3-methally)NiBr]2 with biphosphine monoxides and AgSbF6. The ligands are coordinated in a bidentate way. Starting from [(η3-all)PdI]2 the cationic complexes [(η3-all)PP(O))]Y (8–14). [PP(O) = dppmO, dppeO, dpppO, dtolpmO;Y = BF4, SbF6, CF3SO3, pTolSO3] were synthesized in good yields. The coordination mode of the ligand is dependent on the backbone and the anion, revealing a monodentate coordination with dppmO for stronger coordinating anions. The intermediates [(η3-all)Pd(I)(PP(O)-κ1-P)] (5–7) [PP(O) = dppmO (5), dppeO (6), dtolpmO (7)] were isolated and characterized. Neutral methyl complexes [(Cl)(Me)Pd(PP(O))] (15–18). [PP(O) = dppmO (15), dppeO (16), dpppO (17), dtolpmO (18)] can easily be obtained in high yields starting from [(cod)PdCl2]. For dppmO two different routes are presented. The structure of [(Me)(Cl)Pd{;Ph2P(CH2-P(O)Ph22-P,O};] · CH2Cl2 (15) with the chlorine atom trans to phosphorus was determined by X-ray diffraction.  相似文献   

4.
A 14-membered tetraaza macrocycle, 2,13-bis(2-carbomethoxyethyl)-5,16-dimethyl-2,6,13,17-tetraazatricyclo[16.4.0.1.1807.12]docosane (L2) bearing two N-CH2CH2COOMe groups, and its nickel(II) and copper(II) complexes have been prepared and characterized. The nickel(II) and copper(II) complexes of 2-(2-carbomethoxyethyl)-5,16-dimethyl-2,6,13,17-tetraazatricyclo[16.4.0.1.1807.12]docosane (L3) containing one N-CH2CH2COOMe group have also been prepared. The crystal structure of [NiL2](ClO4)2 shows that the complex has a slightly distorted trans-octahedral coordination geometry with two relatively short axial Ni-O (N-CH2CH2COOMe group) bonds (2.136(3) Å). In various solvents, however, a considerable proportion of [NiL2]2+ exists as a square-planar form, in which the functional pendant arms are not involved in coordination. The proportion of the square-planar isomer varies with solvents in the order of nitromethane ? acetonitrile < H2O < DMF ? DMSO. In the case of [CuL2](ClO4)2, only one N-CH2CH2COOMe group is involved in coordination. The N-CH2CH2COOMe group of [NiL3](ClO4)2 is not directly involved in coordination even in the solid state, though the functional group of [CuL3](ClO4)2 is coordinated to the metal ion.  相似文献   

5.
The reaction of [N(PPh3)2]2[Ni6(CO)12] with Cu(PPh3)xCl (x=1, 2), as well as the degradation of [N(PPh3)2]2[H2Ni12(CO)21] with PPh3, affords the new and unstable dark orange–brown [N(PPh3)2]2[Ni9(CO)16].THF salt in low yields. This salt has been characterized by a CCD X-ray diffraction determination, along with IR spectroscopy and elemental analysis. The close-packed two-layer metal core geometry of the [Ni9(CO)16]2− dianion is directly related to that of the bimetallic [Ni6Rh3(CO)17]3− trianion and may be envisioned to be formally derived from the hcp three-layer geometry of [Ni12(CO)21]4− by the substitution of one of the two outer [Ni3(CO)3(μ−CO)3]2− layers with a face-bridging carbonyl group.  相似文献   

6.
It is shown that the reaction of RhCl3·3H2O with acetonitrile normally produces mixtures of mer- and fac-[RhCl3(CH3CN)3] (1a and 1b, respectively). The IR and 1H NMR spectra of these isomers were re-investigated. Their two-dimensional (103Rh,1H) NMR spectra were also recorded. Equilibrium and exchange studies of 1a and 1b in CD3C were performed. It was found that in 1a the exchange rate of the nitrile molecule trans to Cl is much faster than those of mutually trans nitriles. Also the nitrile molecules in 1b underwent fast exchange in CD3CN; however, their rate was slightly faster than that of the more labile CH3CN in 1a. The X-ray crystal structure of mer-[RhCl3(CH3CN)3]·CH3CN (1c) was determined. Crystal data: triclinic space group .  相似文献   

7.
A crystal and molecular structure determination of MnCl2(bpy) showed that it exists as polymeric octahedral [MnCl2(bpy)]n. [MnCl2(bpy)n crystallizes in the monoclinic space group I2/a with A = 7.007(1), B = 9.200(1), C = 16.495(1) Å, β = 91.313(5)° and Z = 4. On the basis of 979 unique observed reflections with I 2.5σ(I) the structure was refined to R = 0.032.  相似文献   

8.
The coordination capability of the octaaza 24-membered (L1) and the tetraoxotetraaza 28-membered (L2) macrocycle ligands - with different sizes, nature and number of the donor atoms - has been investigated with nitrate and perchlorate Cd(II) salts. The complexes were prepared in 1:1 and 2:1 Cd:L molar ratio. The characterization by elemental analysis, IR, LSI mass spectrometry, conductivity measurements and 1H NMR spectroscopy, together with the crystal structure of the complexes [CdL1](NO3)2 · 0.5H2O, [CdL1](ClO4)2 and [CdL2(CH3CN)2](ClO4)2 · CH3CN · H2O confirms the formation of mononuclear complexes in all cases. The [CdL1](NO3)2 · 0.5H2O and [CdL1](ClO4)2 present a mononuclear endomacrocyclic structure with the metal ion coordinated by the eight donor nitrogen atoms from the macrocyclic backbone in a square antiprism geometry. The complex [CdL2(CH3CN)2](ClO4)2 · CH3CN · H2O is also mononuclear, but the cadmium ion is in an octahedral environment coordinated by four amine nitrogen atoms from the macrocyclic framework and two nitrogen atoms from two acetonitrile molecules. The ether oxygen atoms from the ligand are not coordinated.  相似文献   

9.
Reaction of LaCl3·7H2O containing small amounts of La(NO3)3·7H2O as an impurity with 12-crown-4 or 18-crown-6 in 3:1 CH3CN:CH3OH resulted in the isolation of the mixed anion complexes [LaCl2(NO3)(12-crown-4)]2, [La(NO3)(OH2)4(12-crown-4)]Cl2·CH3CN and [LaCl2(NO3)(18-crown-6)]. The nine-coordinate dimer, [LaCl2(NO3)(12-crown-4)]2, has all of the anions in the inner coordination sphere and La3+ has a capped square antiprismatic geometry. It crystallizes in the orthorhombic space group Pbca with (at −150 °C) a = 12.938(6), B = 15.704(3), C = 13.962(2) Å, and Dcalc = 2.08 g cm−3 for Z = 4. The second complex isolated from the same reaction, [La(NO3)(OH2)4(12-crown-4)]Cl2·CH3CN, has the bidentate nitrate anion in the inner coordination sphere but the two chloride anions are in a hydrogen bonded outer sphere. This complex is ten-coordinate 4A,6B-expanded dodecahedral and crystallizes in the monoclinic space group P21 with (at 20 °C) A = 7.651(2), B = 11.704(7), C = 11.608(4) Å, β = 95.11(2)°, and Dcalc = 1.80 g cm−3 for Z = 2. The 18-crown-6 complex, [LaCl2(NO3)(18-crown-6)], has all inner sphere anions and has ten-coordinate 4A,6B-expanded dodecahedral La3+ centers. It crystallizes in the orthorhombic space group Pbca with (at 20 °C) a = 14.122(7), B = 13.563(5), C = 19.311(9) Å, and Dcalc = 1.89 g cm−3 for Z = 8.  相似文献   

10.
Two ruthenium(II) complexes with polypyridyl, Ru(bipy)2(phen)](ClO4)2·H2O (1) and [Ru(bipy)2(Me-phen)](ClO4)2 (2), (phen = 1,10-phenanthroline, bipy = 2,2′-bipyridine, Me-phen = 5-methyl-1,10-phenanthroline), were synthesized and characterized by IR, MS and NMR spectra. Their structures were determined by single crystal X-ray diffraction techniques. The strong steric interaction between the polypyridyl ligands was relieved neither by the elongation of the Ru---N bonds nor increase of the N---Ru---N bite angles. The coordination sphere was distorted to relieve the ligand interaction by forming specific angles (δ) between the polypyridyl ligand planes and coordination planes (N---Ru---N), and forming larger twisted angles between the two pyridine rings for each bipy. The bond distances of Ru---N(bipy) and Ru---N(phen) were virtually identical with experimental error, as expected of π back-bonding interactions which statistically involve each of the ligands present in the coordination sphere.  相似文献   

11.
Two novel tetracopper(I) and tetrasilver(I) complexes [Cu4(atdz)6](ClO4)4·2CH3OH (1) and [Ag4(atdz)6](ClO4)4 (2), have been prepared using 2-amino-1,3,4-thiadiazole (atdz), and their crystal structures and properties have been determined. On each tetranuclear complex, two Cu or Ag atoms (M) are bridged by two atdz ligands to form a six-membered N2M2N2 framework. The two N2M2N2 frameworks are in parallel linked by another atdz ligand to provide the tetranuclear structure with a rectangular M4 core. The four Cu or Ag atoms possess a trigonal-square geometry. The two adjacent MM separations are (3.096(1) and 3.412(1) Å) and (3.316(2) and 3.658(2) Å) for 1 and 2, respectively. On both tetranuclear complexes there are two species of hydrogen bonds between the ClO4 − anions and the NH2 group of atdz ligands. It is proposed that the hydrogen bonds are related to the stabilization of the tetranuclear structure during the crystallization process.  相似文献   

12.
Two NiII complexes of 1,5-diazacyclooctane (DACO), [Ni(DACO)2]Br2 (I) and [Ni(DACO)2]Br·ClO4 (II) have been newly synthesized and characterized. Single crystal X-ray diffraction analysis of DACO and both NiII complexes reveals that DACO takes boat/chair conformation in the solid state and its NiII complexes. In complex I, NiII ion is at the center of symmetry, which is four-coordinated by nitrogen donors of DACO. However, in complex II, an unexpected coordination mode of [M(DACO)2]2+ (M=CuII and NiII) was found, in which two DACO ligands are related to each other by a mirror plane and the coordination sphere of NiII is a distorted planar geometry. Furthermore, complexes I and II form quite different packing patterns (macrocycle or chain) through hydrogen bonds, which may be a key role to stabilize the crystals. The results of theoretical calculation indicate that complex I has thermodynamic stability, while II has chemical stability. Therefore, both of them have the probability to be obtained from different reaction processes or conditions.  相似文献   

13.
The dimer [(dippe)Ni(μ-S)]2 reacts with organic electrophiles to give the alkylated species [(dippe)2Ni2(μ-S)(μ-SR)]+. Stronger alkylating agents lead to double alkylation and cleavage of the dimer. Protonation similarly occurs with strong acids. The structures of several of these species have been determined.  相似文献   

14.
A novel five-coordinate rhenium(III)-thiolato complex, Re(SCH2C6H4OCH3-p)3(PPh3)2 has been isolated during the reaction of trans-ReOCl3(PPh3)2 with p-methoxybenzyl mercaptan. In the unexpected structure that was acquired, the central metal has undergone a reduction from Re(V) to Re(III). The five-coordinate Re(III) complex has been characterized by spectroscopic methods, elemental analysis and X-ray crystallography. X-ray crystallographic studies showed the coordination geometry around rhenium to be that of a trigonal bipyramid. The basal plane is defined by three sulfur atoms of the monodentate ligand, while the two apical positions are occupied by two phosphines of the precursor.  相似文献   

15.
Treatment of a THF solution of trans-[ReCl(N2)L4] (L = PMePh2) with a cyanamide, NCNR2 (R = Me, Et or H) or with cyanoguanidine, NCNC(NH2)2 , yields mer-[ReCl(N2)(NCNR2)L3] (1) or mer-[Re(N2)[Re(N2){NCNC(NH2)2}2L3]Cl (2), respectively, which, to our knowledge, are the first mixed dinitrogen-cyanamide-type complexes to be reported. The former products (1, R=Me or Et) can also be obtained from reaction of the benzoyldiazenido complex [ReCl2(NNCOPh)L3] with NCNR2 in refluxing methanol; the Re(II) complex mer-[ReCl2(NCNEt2)L3] (3) is also formed (conceivably via an unusual homolysis of the C---N bond of the benzoyldiazenido ligand) and its crystal structure is reported. It shows an unusual pyramidal conformation at the amine N atom of the diethylcyanamide ligand which also exhibits a significant structural trans influence on the phosphine, behaving as a stronger net electron donor than the latter ligand.  相似文献   

16.
The 1,3-oxazine complexes cis- and trans-[PtCl2{ C(R)OCH2CH2C}H22] (cis: R=CH3 (1a), CH2CH3 (2a), (CH3)3C (3a), C6H5 (4a); trans:R =CH3 (1b), C6H5 (4b)) were obtained in 51-71% yield by reaction in THF at 0 °C of the corresponding nitrile complexes cis- and trans-[PtCl2(NCR)2] with 2 equiv. of OCH2CH2CH2Cl, generated by deprotonation of 3-chloro-1-propanol with n-BuLi. The cationic nitrile complexes trans-[Pt(CF3)(NCR)(PPh3)2]BF4 (R=CH3, C6H5) react with 1 equiv, of OCH2CH2CH2Cl to give a mixture of products, including the corresponding oxazine derivatives trans-[Pt(CF3){ CH2}(PPh3)2]BF4 (5 and 6), the chloro complex trans- [Pt(CF3)Cl(PPh3)2] and free oxazine H2. For short reaction times (c. 5–15 min) the oxazine complexes 5 and 6 could be isolated in modest yield (37–49%) from the reaction mixtures and they could be separated from the corresponding chloro complex (yield 40%) by taking advantage of the higher solubility of the latter derivative in benzene. For longer reaction times (> 2 h), trans-[Pt(CF3)Cl(PPh3)2] was the only isolated product. Complex 6 was crystallographically characterized and it was found to contain also crystals of trans- [PtCl{ H2}(PPh3)2]BF4, which prevented a more detailed analysis of the bond lengths and angles within the metal coordination sphere. The 1,3-oxazine ring, which shows an overall planar arrangement, is characterized by high thermal values of the carbon atoms of the methylene groups indicative of disordering in this part of the molecule in agreement with fast dynamic ring processes suggested on the basis of 1H NMR spectra. It crystallizes in the trigonal space group P , with a=22.590(4), b=15.970(3) Å, γ=120°, V=7058(1) Å3 and Z=6. The structure was refined to R=0.059 for 3903 unique observed (I3σ(I)) reflections. A mechanism is proposed for the conversion of nitrile ligands to oxazines in Pt(II) complexes.  相似文献   

17.
The reaction of the neutral Tc(V) phenylimido complex [TcCl3(NPh)(PPh3)2] with excess PMe2Ph in refluxing MeOH gives the cationic, tris-dimethylphenylphosphine complex [TcCl2(NPh)(PMe2Ph)3]+, which is isolated as the tetraphenylborate salt. The IR spectrum of the crystalline product shows a medium intensity band at 1102 cm−1 which is assigned to ν(TcN) from the phenylimido core. The 1H NMR spectrum of the diamagnetic complex shows a series of multiplets in the aryl region and three distinct signals near 2 ppm from the phosphine methyl groups. The X-ray crystal structure, which is the first for a cationic technetium organoimido complex, shows a meridional arrangement of phosphine ligands with a chloride ligand coordinated trans to the phenylimido unit. The TcN bond length of 1.711(2) Å is consistent with the dianionic nature of the organonitrogen core. The Tc---N---C bond angle of 178.8(2)° reflects the sp hybridization of the phenylimido nitrogen atom. The coordination geometry is best described as a distorted octahedron. Crystal data for C54H58BCl2NP3Tc: triclinic space group . Structure solution based on 9986 observed reflections converged at R = 3.65%, Rw = 5.43%, GOF = 1.82.  相似文献   

18.
Copper(II) complexes were synthesized and characterized by means of elemental analysis, IR and visible spectroscopies, EPR and electrochemistry, as well as X-ray structure crystallography. The group consists of discrete mononuclear units with the general formula [Cu(II)(Hbpa)2](A)2·nH2O, where Hbpa=(2-hydroxybenzyl-2-pyridylmethyl)amine and A=ClO4 −, n=2 (1), CH3COO, n=3 (2), NO3 −, n=2 (3) and SO4 2−, n=3 (4). The structures of the ligand Hbpa and complex 1 have been determined by X-ray crystallography. Complexes 1–4 have had their UV–Vis spectra measured in both MeCN and DMF. It was observed that the compounds interact with basic solvents, such that molecules coordinate to the metal in axial positions in which phenol oxygen atoms are coordinated in the protonated forms. The values were all less than 1000 M−1 cm−1. EPR measurements on powdered samples of 1–3 gave g/A values between 105 and 135 cm−1, typical for square planar coordination environments. Complex 4·3H2O exhibits a behaviour typical for tetrahedral coordination. The electrochemical behaviour for complexes 1 and 2 was studied showing irreversible redox waves for both compounds.  相似文献   

19.
Five new complexes of general formula: [Ni(RSO2NCS2)(dppe)], where R = C6H5 (1), 4-ClC6H4 (2), 4-BrC6H4 (3), 4-IC6H4 (4) and dppe = 1,2-bis(diphenylphosphino)ethane and [Ni(4-IC6H4SO2NCS2)(PPh3)2] (5), where PPh3 = triphenylphosphine, were obtained in crystalline form by the reaction of the appropriate potassium N-R-sulfonyldithiocarbimate K2(RSO2NCS2) and dppe or PPh3 with nickel(II) chloride in ethanol/water. The elemental analyses and the IR, 1H NMR, 13C NMR and 31P NMR spectra are consistent with the formation of the square planar nickel(II) complexes with mixed ligands. All complexes were also characterized by X-ray diffraction techniques and present a distorted cis-NiS2P2 square-planar configuration around the Ni atom. Quantum chemical calculations reproduced the crystallographic structures and are in accord with the spectroscopic data. Rare C-H···Ni intramolecular short contact interactions were observed in the complexes 1-5.  相似文献   

20.
Two new rhenium(IV) mononuclear compounds of formula NBu4[ReBr4(OCN)(DMF)] (1) and (NBu4)2[ReBr(OCN)2(NCO)3] (2) (NBu4 = tetrabutylammonium cation, OCN = O-bonded cyanate anion, NCO = N-bonded cyanate anion and DMF = N,N-dimethylformamide) have been synthesized and their crystal structures determined by single-crystal X-ray diffraction. 1 crystallizes in the monoclinic system with the space group P21/n, whereas 2 crystallizes in the triclinic one with as space group. In both complexes the rhenium atom is six-coordinated, in 1 by four Br atoms in the equatorial plane, and two trans-oxygen atoms, one of a DMF molecule and another one from a cyanato group, while in 2 by one bromide anion and five cyanate ligands, two of which are O-bonded and three N-bonded, forming a somewhat distorted octahedral surrounding. Magnetic susceptibility measurements on polycrystalline samples of 1 and 2 in the temperature range 1.9-300 K are interpreted in terms of magnetically isolated spin quartets with large values of the zero-field splitting (|2D| is ca. 41.6 and 39.2 cm−1 for 1 and 2, respectively).  相似文献   

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