共查询到20条相似文献,搜索用时 31 毫秒
1.
H. Sadaf S. Ahmad S. Sharif I. U. Khan M. Akkurt S. W. Ng M. I. Khan S. A. Bashir M. Mufakkar 《Journal of Structural Chemistry》2012,53(1):151-155
Two mercury(II) cyanide complexes of N-ethylthiourea (Ettu) and N-propylthiourea (Prtu) ligands, [Hg(Ettu)2(CN)2] (1) and [Hg(Prtu)2(CN)2] (2), were prepared and their crystal structures were determined by X-ray crystallography. In both structures, the mercury atom
is coordinated to two sulfur atoms of thioureas and two cyanide carbon atoms in a pseudo-tetrahedral mode with the bond angles
in the range of 90.52(11)–162.2(3)°. The structures are stabilized by N-H—S, N-H—N, and C-H—N intramolecular and intermolecular
hydrogen bonds. 相似文献
2.
Soraia Meghdadi Mehdi Amirnasr Mohammad H. Habibi Ahmad Amiri Fatemeh Ahmadi Keiko Kihara Takayoshi Suzuki Hamid Reza Bijanzadeh 《Transition Metal Chemistry》2008,33(7):879-886
The structure, spectroscopic, and electrochemical properties of [Co{(BA)2pn}(L)2]ClO4 complexes, where (BA)2pn = N,N′-bis(benzoylacetone)-1,3-propylenediimine dianion and the two ancillary ligands (L) are pyridine, py (1), and 4-methylpyridine, 4-Mepy (2), have been investigated. These complexes have been characterized by elemental analyses, IR, UV–Vis and 1H-NMR spectroscopy. The crystal structure of [Co{(BA)2pn}(py)2]ClO4 (1) has been determined by X-ray diffraction. The coordination geometry around cobalt(III) is best described as a distorted
octahedron. The electrochemical reduction of these complexes at a glassy carbon electrode in acetonitrile solution indicates
that the first reduction process corresponding to CoIII–CoII is electrochemically irreversible, which is accompanied by the dissociation of the axial N(py)–cobalt bonds. This process
becomes quasi-reversible upon the addition of excess py ligands. The second reduction step of CoII/I shows reversible behavior and is not influenced by the nature of the axial ligands.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献
3.
Shafqat Nadeem Muhammad Khawar Rauf Michael Bolte Saeed Ahmad Syed Ahmed Tirmizi Maliha Asma Abdul Hameed 《Transition Metal Chemistry》2010,35(5):555-561
Palladium(II) bromide complexes of thioamides having the general formulae [PdL2Br2] and [PdL4]Br2 where L = Thiourea (Tu), Methylthiourea (Metu), Dimethylthiourea (Dmtu), Tetramethylthiourea (Tmtu), Imidazolidine-2-thione
(Imt), Mercaptopyridine (Mpy), Mercaptopyrimidine (Mpm) and Thionicotinamide (Tna) were prepared by reacting K2[PdCl4] with KBr and the corresponding thioamides. The complexes were characterized by elemental analysis, IR and NMR spectroscopy,
and one of them, [Pd(Tmtu)4]Br2 (1) by X-ray crystallography. The crystal structure of 1 shows a square-planar coordination environment around the Pd(II) atoms with the average cis and trans S–Pd–S bond angles of 90.0° and 180.0°, respectively. The synthesized complexes were screened for antibacterial effects,
and the results showed that the complexes exhibit significant activities against both gram positive and gram negative bacteria. 相似文献
4.
The ortho-metalated complex [Pd(x){κ
2
(C,N)-[C6H4CH2NRR′ (Y)}] (2a–4a and 2b–3b) was prepared by refluxing in benzene equimolecular amounts of Pd(OAc)2 and secondary benzylamine [a, EtNHCH2Ph; b, t-BuNHCH2Ph followed by addition of excess NaCl. The reaction of the complexes [Pd(x){κ
2
(C,N)-[C6H4CH2NRR′ (Y)}] (2a–4a and 2b–3b) with a stoichiometric amount of Ph3P=C(H)COC6H4-4-Z (Z = Br, Ph) (ZBPPY) (1:1 molar ratio), in THF at low temperature, gives the cationic derivatives [Pd(OC(Z-4-C6H4C=CHPPh3){κ
2
(C,N)-[C6H4CH2NRR′(Y)}] (5a–9a, 4b–6b, and 4b′–6b′), in which the ylide ligand is O-coordinated to the Pd(II) center and trans to the ortho-metalated C(6)H(4) group, in an “end-on
carbonyl”. Ortho-metallation, ylide O-coordination, and C-coordination in complexes (5a–9a, 4b–6b, and 4b′–6b′) were characterized by elemental analysis as well as various spectroscopic techniques. 相似文献
5.
A zwitterionic trichloroplatinum(II) complex PtCl3(4,4′-bpy-N-nBu) (1) was prepared by an aqueous reaction of [4,4′-bpy-N-nBu]Cl with K2PtCl4, and was characterized by 1H-n.m.r. and IR spectroscopy as well as elemental analysis. Dissolving (1) into dmso-d
6 at 25 °C yields a mixture of the complexes, cis-PtCl2(4,4′-bpy-N-nBu)(dmso-d
6) (2-cis), trans-PtCl2(4,4′-bpy-N-nBu)(dmso-d
6) (2-trans), [4,4′-bpy-N-nBu]Cl and PtCl2(dmso-d
6)2. Ratio of the products in the dmso-d
6 solution changed depending on the temperature and the total concentration of the complexes. These compounds are in equilibrium
via isomerization reaction between (2-cis) and (2-trans) and via displacement reaction of the alkylbipyridinium ligand of
(2-cis) and (2-trans) with dmso-d
6 to form [4,4′-bpy-N-nBu]Cl and PtCl2(dmso-d
6)2. 相似文献
6.
Two copper(I) complexes [Cu(Cin2bda)2]ClO4 (I) and [Cu(Ncin2bda)2]ClO4 (II) have been prepared by the reaction of the ligands N2,N2′-bis(3-phenylallylidene)biphenyl-2,2′-diamine (L1) and N2,N2′-bis[3-(2-nitrophenyl)allylidene]biphenyl-2,2′-diamine (L2) and copper(I) salt. These compounds were characterized by CHN analyses, 1H NMR, IR, and UV-Vis spectroscopy. The C=N stretching frequency in the copper(I) complexes shows a shift to a lower frequency
relative to the free ligand due to the coordination of the nitrogen atoms. The crystal and molecular structure of II was determined
by X-ray single-crystal crystallography. The coordination polyhedron about the copper(I) center in the complex is best described
as a distorted tetrahedron. A quasireversible redox behavior was observed for complexes I and II.
The article is published in the original. 相似文献
7.
In the compound [Ni(Bptc)2(Bimb)2(H2O)2] (I), where H4Bptc is 3,3′,4,4′-biphenyltetracarboxylic acid; Bimb is 4,4′-bis(1-imidazolyl)biphenyl), Ni(II) has a distorted octahedral coordination geometry, which was bonded with two N atoms from two
Bimb ligands, two O atoms from two H2Bptc2− ligands and two water O atoms. The crystal structure of compound I is stabilized by the π-π-stacking and hydrogen bonds interaction. 相似文献
8.
K. Ramalingam R. Thiruneelakandan G. Bocelli L. Righi 《Transition Metal Chemistry》2012,37(3):265-270
The complexes trans-[Ni(4-MP)2(NCS)2]·MeCN (1) and trans-[Ni(3-MP)2(NCS)2] (2) (4-MP = tri(4-methylphenyl)phosphine, 3-MP = tri(3-methylphenyl)phosphine) were prepared and characterized by IR, UV–visible,
NMR spectra, CV, TGA and single crystal X-ray crystallography. Both the complexes have planar geometry and are diamagnetic.
The Ni–P distances in both complexes are relatively short as a result of strong back donation from nickel to phosphorus. The
phenyl rings in the 3-MP analogue (2) show increased pitching with reference to the plane formed by the ipso carbons due to increased steric effects. For complex
(2), the N–Ni–N and P–Ni–P angles are significantly lower than the almost linear N–Ni–N and N–Ni–P angles observed for both
complex (1) and trans-[Ni(PPh3)2(NCS)2]. This observation indicates that the 3-methylphosphine ligand forces complex (2) to distort towards a tetrahedral geometry. IR spectra of both complexes show strong bands around 2,090 cm−1 due to N-coordinated thiocyanate, while the electronic spectra contain d–d transitions around 452 nm. Cyclic voltammograms
show that the irreversible one-electron reduction potentials increase in the following order: trans- [Ni(PPh3)2(NCS)2] < trans- [Ni(3-MP)2(NCS)2] < trans-[Ni(4-MP)2(NCS)2], revealing the electron releasing effect of the methyl groups. The planar complexes exhibit interallogony in coordinating
solvents. 相似文献
9.
Saeed Ahmad Mohammed Fettouhi Thierry Roisnel Mshari A. Alotaibi Abdulrahman I. Alharthi Muhammad Riaz Malik 《Journal of Coordination Chemistry》2017,70(21):3692-3701
Cadmium(II) complexes, catena-poly[bis(thiocyanato-κN)bis(N-methylthiourea)cadmium(II)], [Cd(Metu)2(NCS)2]n (1) and dicyanidobis(N-methylthiourea)cadmium(II), [Cd(Metu)2(CN)2] (2) were prepared and their structures were determined by single crystal X-ray analysis. In 1, the cadmium(II) ion is bound to four sulfur atoms of bridging Metu ligands and two nitrogen atoms of thiocyanate adopting a distorted octahedral environment. In 2, the geometry around cadmium is distorted tetrahedral attained by two cyanide ions and two methylthiourea molecules bound through the sulfur atoms. The crystal structures of both complexes show intra and intermolecular hydrogen bonding interactions. The complexes were also characterized by IR and NMR spectroscopy and the spectroscopic data were discussed in terms of the nature of bonding. 相似文献
10.
New mixed-ligand copper(I) complexes, [Cu(Phca2en)(PPh3)X], [Phca2en = N,N′-bis(β-phenylci-nnamaldehyde)-1,2-diiminoethane and X=Cl (1), Br (2), I (3), NCS (4), N3 (5)] have been synthesized and characterized by various techniques. 1H and 13C-NMR and IR spectral data of these copper(I) complexes are compared with the free ligand to elucidate some structural features. The structures of [Cu(Phca2en)(PPh3)Br] (2) and [Cu(Phca2en)(PPh3)I] (3) have been determined from single-crystal data showing that the coordination geometry around copper atom is a distorted tetrahedron. Furthermore, these Cu(I) complexes exhibit supramolecular motifs of the type multiple phenyl embraces resulting from attractive interactions between phenyl rings of PPh3 moieties. The presence of the C–H…Cu weak intramolecular hydrogen bonds, due to the trapping of C–H bonds in the vicinity of the metal atoms, is also reported. 相似文献
11.
Mozaffar Asadi Maryam Mohammadikish Khosro Mohammadi 《Central European Journal of Chemistry》2010,8(2):291-299
Four Schiff base ligands, salabza-H2 = N,N′-bis(salicylidene)-2-aminobenzylamine, were synthesized by condensation of one mole of 2-aminobenzylamine and two moles of
salicylaldehyde and/or two moles of substituted salicylaldehyde (5-OMe, 5-Br, 5-NO2). All the four Schiff bases and their Mn(II), Co(II), Cu(II) and Zn(II) complexes are characterized by UV-Vis, FT-IR, 1H NMR spectroscopy, mass spectrometry and elemental analysis. The formation constants and the Gibbs free energies were measured
spectrophotometrically for 1:1 complexes in methanol in constant ionic strength (I = 0.1 mol dm−3 NaClO4) and at 25°C. The data refinement was carried out with the SQUAD program. The trend of formation constants of H2L1 with M(II) follows the order: Mn(II) (3.97) < Zn(II) (4.30) < Co(II) (4.89) < Cu(II) (5.73) 相似文献
12.
H. M. Ye N. Ren H. Li J. J. Zhang S. J. Sun L. Tian 《Journal of Thermal Analysis and Calorimetry》2010,101(1):205-211
The complex of [Nd(BA)3bipy]2 (BA = benzoic acid; bipy = 2,2′-bipyridine) has been synthesized and characterized by elemental analysis, IR spectra, single
crystal X-ray diffraction, and TG/DTG techniques. The crystal is monoclinic with space group P2(1)/n. The two–eight coordinated Nd3+ ions are linked together by four bridged BA ligands and each Nd3+ ion is further bonded to one chelated bidentate BA ligand and one 2,2′-bipyridine molecule. The thermal decomposition process
of the title complex was discussed by TG/DTG and IR techniques. The non-isothermal kinetics was investigated by using double
equal-double step method. The kinetic equation for the first stage can be expressed as dα/dt = A exp(−E/RT)(1 − α). The thermodynamic parameters (ΔH
≠, ΔG
≠, and ΔS
≠) and kinetic parameters (activation energy E and pre-exponential factor A) were also calculated. 相似文献
13.
H. Ur Rehman S. Ahmad H. Ajaz M. Hanif M. Altaf H. Stoeckli-Evans 《Journal of Structural Chemistry》2011,52(1):160-165
A polymeric silver(I) complex, bis(N-methylthiourea)silver(I) nitrate, {[Ag(Metu)2]NO3}
n
is prepared and its crystal structure is determined. The compound crystallizes in the monoclinic C2/c space group. In the structure, distorted AgS4 tetrahedra are linked through the sulfur atoms of the Metu ligand to form isolated infinite chains of the type [Ag(SR)2]
n
n+. The cationic chains are separated from each other by nitrate ions that do not coordinate to the metal ion. The chains are
bridged via N-H...O hydrogen bonds involving the nitrate ions. The complex exhibits an Ag—Ag separation of ∼3.21 ? indicating
the existence of significant argentophilic interactions. An upfield shift in the >C=S resonance of Metu in 13C NMR and downfield shift in the N-H resonance in 1H NMR are consistent with sulfur coordination to silver(I). 相似文献
14.
Shafqat Nadeem Muhammad Khawar Rauf Saeed Ahmad Masahiro Ebihara Syed Ahmed Tirmizi Sarfaraz Ahmed Bashir Amin Badshah 《Transition Metal Chemistry》2009,34(2):197-202
Palladium(II) complexes of thiones having the general formula [Pd(L)4]Cl2, where L = thiourea (Tu), methylthiourea (Metu), N,N′-dimethylthiourea (Dmtu), and tetramethylthiourea (Tmtu) were prepared by reacting K2[PdCl4] with the corresponding thiones. The complexes have been characterized by elemental analysis, IR and NMR spectroscopy, and
two of these, [Pd(Dmtu)4]Cl2 · 2H2O (1) and [Pd(Tmtu)4]Cl2 (2), by X-ray crystallography. An upfield shift in the >C=S resonance of thiones in 13C NMR and downfield shift in N–H resonance in 1H NMR are consistent in showing sulfur coordination with palladium(II). The crystal structures of the complexes show a square-planar
coordination environment around the Pd(II) ions with the average cis and trans S–Pd–S bond angles of 89.64° and 173.48°, respectively.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users.
An erratum to this article can be found at 相似文献
15.
One new metal – organic coordination framework formulated as [{Cu(4,4′-bipy)(CH3COO)2}·3H2O]n (1) (where 4,4′-bipy=4,4′-bipyridine) has been hydrothermally synthesised and characterised by elemental analysis, IR and electronic
spectroscopy, variable temperature magnetic moment measurement and single crystal X-ray diffraction study. Single crystal
X-ray analysis reveals that 1 is one dimensional polymeric compound in which acetate ligand shows both mono- and bidentate bonding mode, and 4,4′-bipy
acts as bridging ligand which supports the formation of infinite chains. The global feature of the χ
M
T vs. T curve in 1 is characteristic of moderate antiferromagnetic interaction and the best fit parameters from 300 down to 2 K are found as
J = −78.7 cm−1. 相似文献
16.
Prithwiraj Byabartta 《Russian Journal of General Chemistry》2009,79(6):1214-1217
The reaction of [Ni(dppa)(Cl)2] or [Ni(dppa)(Br)2] with AgOTf gives [Ni(dppa)(OTf)2], which then form [Ni(dppa)(RaaiR)](OSO2CF3)2 under the action of arylazoimidazole(RaaiR) in a dichloromethane medium [RaaiR′ = p-R-C6H4-N=N-C3H2-NN-1-R′, (I–III), abbreviated as N,N′-chelating agent, where N(imidazole) and N(azo) represent N and N’, respectively; R = H (a), Me (b), Cl (c) and R′ = Me (I), CH2CH3 (II), CH2Ph (III), OSO2CF3 is the triflate anion]. The 1H NMR spectral measurements suggest that a bound azoimine is responsible for a number of signals of phenyl protons in the
aromatic region. The molecules of the complexes contain a number of different carbon atoms which gives a number of different
peaks in the 13C (1H) NMR spectrum. The text was submitted by the author in English.
The text was submitted by the author in English. 相似文献
17.
Giuseppe Tresoldi Santo Di Pietro Dario Drommi Santo Lanza 《Transition Metal Chemistry》2010,35(2):151-158
The solvento species obtained by the treatment of cis-RuCl2(N,N-L)2 [L = di-2-pyridyl sulfide (dps), di-2-pyrimidyl sulfide (dprs)] with AgPF6, reacted with dithioethers L′ [L′ = 2,6-bis(2-pyridylthiomethyl)pyridine (pytmp), 2,6-bis(2-pyrimidylthiomethyl)pyridine (prtmp) and 2,6-bis{2-(4-methyl)pyrimidylthiomethyl}
pyridine (mprtmp)] to afford the compounds [Ru(N,N-L)2(N,S-L′)][PF6]2. The 1H NMR spectra indicate that L′ is chelated through S and N atoms with the formation of a four-membered ring. As a consequence, the ruthenium and sulfur
atoms are stereogenic centers with ∆ and Λ and (R) and (S) configurations, respectively. NMR spectra, at low temperatures, show that two invertomers, of similar abundance, as enantiomeric
couples ∆S, ΛR and ∆R, ΛS are present. In the methylene region, four AB systems are observed that in both the species contain
two non-equivalent methylene groups. Variable-temperature NMR spectra and EXSY experiments show that the sulfur inversion
produces an exchange between the invertomers. The one-dimensional band-shape analysis of the exchanging methylene signals
showed that the energy barriers for the process are in the 43–52 kJ mol−1 range. The possible mechanisms of the sulfur inversion are discussed. 相似文献
18.
Hasan Marai Ewa Kita Emilia Kiersikowska Sylwia Kuchta Anna Bajek Tomasz Drewa 《Transition Metal Chemistry》2012,37(4):337-344
Three chromium(III) complexes with asparagine (Asn) and histidine (His) of the [Cr(ox)2(Aa)]2− type, where Aa = N,O–Asn, N,O–His or N,N′–His, were obtained and characterized in solution. The complexes with N,O–Aa undergo acid-catalysed aquation to give a free amino acid and cis-[Cr(ox)2(H2O)2]−, whereas the complex with N,N′–His undergoes parallel reaction paths: (1) isomerization to the N,O–His complex and (2) liberation of an oxalate ligand. Kinetics of the N,O–Aa complexes in HClO4 media were studied spectrophotometrically under pseudo-first-order conditions. The absorbance changes were attributed to
the chelate ring opening at the Cr–N bond. The linear dependence of rate constants on [H+] was established, and a mechanism for the chelate ring cleavage was postulated. The existence of a metastable intermediate
with O-monodentate Aa ligand was proved experimentally. Effect of [Cr(ox)2(Aa)]2− on 3T3 fibroblasts proliferation was studied. The tests revealed low cytotoxicity of the complexes. Complexes with Ala, His
and Cys are good candidates for biochromium sources. 相似文献
19.
Bin Peng Hui Chao Bin Sun Feng Gao Liang-Nian Ji Jian Zhang 《Transition Metal Chemistry》2007,32(2):271-277
Two novel cobalt(III) mixed-polypyridyl complexes
[Co(bpy)2(dpta)]3+ and [Co(bpy)2(amtp)]3+ (bpy = 2,2′-bipyridine, dpta = dipyrido-[3,2-a;2′,3′-c]-thien-[3,4-c]azine, amtp = 3-amino-1,2,4-triazino[5,6-f]-1,10-phenanthroline)
have been synthesized and characterized. The interaction of CoIII complexes with calf thymus DNA was investigated by spectroscopic and viscosity measurements. Results suggest that the two
complexes bind to DNA via an intercalative mode. Moreover, CoIII complexes have been found to promote the photocleavage of plasmid DNA pBR322 under irradiation at 365 nm. The mechanism studies
reveal that hydroxyl radical (OH•) is likely to be the reactive species responsible for the cleavage of plasmid DNA by [Co(bpy)2(dpta)]3+ and superoxide anion radical (O
2
•−
) acts as the key role in the cleavage reaction of plasmid DNA by [Co(bpy)2(amtp)]3+. 相似文献
20.
Prithwiraj Byabartta 《Russian Journal of Inorganic Chemistry》2010,55(7):1052-1056
Reaction of [Pd(dppe)Cl2/Br2] with AgOTf in a dichloromethane medium followed by ligand addition led to [Pd(dppe)(OSO2CF3)2] and then [Pd(dppe)(RaaiR)](OSO2CF3)2 [RaaiR′ = p-R-C6H4-N=N-C3H2-NN-1-R′, (1–3), abbreviated as a N,N′-chelator, where N(imidazole) and N(azo) are represented by N and N′, respectively; R = H (a), Me (b), Cl (c) and R′ = Me (1), CH2CH3 (2), CH2Ph (3), OSO2CF3 is the triflate anion, dppe = 1,2-bis-(diphenylphosphinoethane)]. 31P “1H” NMR confirmed that due to the two phosphorus atom interaction in the azoimine symmetrical environment one sharp peak was
formed. The 1H NMR spectral measurements suggest that azo-imine link with lot of phenyl protons in the aromatic region. 13C (1H) NMR spectrum, 1H, 1H COSY and 1H, 13C HMQC spectrum assign the solution structure and stereo-retentive conformation in each complex. 相似文献