共查询到20条相似文献,搜索用时 31 毫秒
1.
Dipankar Mishra Andrea Barbieri Hake M. Figgie Shyamal Kumar Chattopadhyay 《Inorganica chimica acta》2007,360(7):2231-2244
Six ruthenium(II) complexes have been prepared using the tridentate ligands 2,6-bis(benzimidazolyl) pyridine and bis(2-benzimidazolyl methyl) amine and having 2,2′-bipyridine, 2,2′:6′,2″-terpyridine, PPh3, MeCN and chloride as coligands. The crystal structures of three of the complexes trans-[Ru(bbpH2)(PPh3)2(CH3CN)](ClO4)2 · 2H2O (2), [Ru(bbpH2)(bpy)Cl]ClO4 (3) and [Ru(bbpH2)(terpy)](ClO4)2 (4) are also reported. The complexes show visible region absorption at 402-517 nm, indicating that it is possible to tune the visible region absorption by varying the ancillary ligand. Luminescence behavior of the complexes has been studied both at RT and at liquid nitrogen temperature (LNT). Luminescence of the complexes is found to be insensitive to the presence of dioxygen. Two of the complexes [Ru(bbpH2)(bpy)Cl]ClO4 (3) and [Ru(bbpH2)(terpy)](ClO4)2 (4) show RT emission in the NIR region, having lifetime, quantum yield and radiative constant values suitable for their application as NIR emitter in the solid state devices. The DFT calculations on these two complexes indicate that the metal t2g electrons are appreciably delocalized over the ligand backbone. 相似文献
2.
Reaction of [Ru(2,2′-bipyridine)(2,2′:6′,2″-terpyridine)Cl]PF6 (abbreviated to [Ru(bipy)(terpy)Cl]PF6) with 0.5 equiv of the bidentate ligand L produces the dinuclear complexes [{Ru(bipy)(terpy)}2(μ-L)](PF6)4 (L = 4,4′-bipyridine 1, 1,4-diisocyanobenzene 2 and pyrazine 3) in moderate yields. Treating [Ru(bipy)(terpy)Cl]PF6 with equal molar of 1,4-diisocyanobenzene affords [Ru(bipy)(terpy)(CNC6H4NC)](PF6)2 (2a). These new complexes have been characterized by mass, NMR, and UV-Vis spectroscopy, and the structures of 1-3 determined by an X-ray diffraction study. Cyclic voltammetric studies suggest that metal communication between the two ruthenium ions increases from 1 to 2 to 3. 相似文献
3.
[Ru(H)(CO)(PPh3)2(α/β-NaiR)](ClO4) (3, 4) are synthesized by the reaction of [Ru(H)(Cl)(CO)(PPh3)3] with 1-alkyl-2-(naphthyl-α/β-azo)imidazole (α-NaiR (3); β-NaiR (4)). One of the complexes [Ru(H)(CO)(PPh3)2(α-NaiMe)](ClO4) (3a) has been structurally established by X-ray diffraction study. Upon addition of Cl2 saturated in MeCN to 3 or 4 gives [Ru(Cl)(CO)(α/β-NaiR)(PPh3)2](ClO4) (for α-NaiR (5); β-NaiR (6)), without affecting metal oxidation state, which were characterized by spectroscopic measurements. The redox property of the complexes is examined by cyclic voltammetry. 相似文献
4.
Ruthenium complexes containing pdon (pdon = 1,10-phenanthroline-5,6-dione) were synthesized. Their spectroscopic and electrochemical properties were examined. The molecular structure with [Ru(pdon)(bpy)2](ClO4)2 ([1](ClO4)2) (bpy = 2,2′-bipyridyl) was determined by single crystal X-ray diffraction. The optically transparent thin-layer electrochemical measurements confirm that the quinone form of [1](ClO4)2 is reduced to the semi-quinone state in acetonitrile (E°′ = −8 mV). Comparing the model complex, [1](ClO4)2, and metal-free pdon, the positive charge on two carbon atoms of the o-quinone group is bigger than that of metal-free pdon. The assemblies of the complexes were finally examined using ligand substitution. 相似文献
5.
A series of ruthenium (II) complexes of formulae trans-[Ru(PPh3)2(L′H)2](ClO4)2 (1), [Ru(bpy)(L′H)2](ClO4)2 (2), [Ru(bpy)2(L′H)](ClO4)2 (3), cis-[Ru(DMSO)2(L′H)2]Cl2 (4), and [Ru(L′H)3](PF6)2 (5) (where L′H = 2-(2′-benzimidazolyl)pyridine) have been synthesized by reaction of the appropriate ruthenium precursor with 1,2-bis(2′-pyridylmethyleneimino)benzene (L). The complexes were characterized by elemental analyses, spectroscopic and electrochemical data. All the complexes were found to be diamagnetic and hence metal is in +2 oxidation state. The molecular structure of trans-[Ru(PPh3)2(L′H)2](ClO4)2 has been determined by the single crystal X-ray diffraction studies. The molecular structure shows that Ru(II) is at the center of inversion of an octahedron with N4P2 coordination sphere. The ligand acts as a bidentate N,N′donor. The electronic spectra of the complexes display intense MLCT bands in the visible region.Cyclic voltammetric studies show quasi-reversible oxidative response at 0.99-1.32 V (vs Ag/AgCl reference electrode) due to Ru(III)/Ru(II) couple. 相似文献
6.
Hena Paul Buddhadeb Sen Tapan Kumar Mondal 《Nucleosides, nucleotides & nucleic acids》2017,36(8):520-542
Two new ruthenium(II) complexes of Schiff base ligands (L) derived from cinnamaldehyde and ethylenediamine formulated as [Ru(L)(bpy)2](ClO4)2, where L1 = N,N’-bis(4-nitrocinnamald-ehyde)ethylenediamine and L2 = N,N’-bis(2-nitrocinnamaldehyde)-ethylenediamine for complex 1 and 2, respectively, were isolated in pure form. The complexes were characterized by physicochemical and spectroscopic methods. The electrochemical behavior of the complexes showed the Ru(III)/Ru(II) couple at different potentials with quasi-reversible voltammograms. The interaction of the complexes with calf thymus DNA (CT-DNA) using absorption, emission spectral studies and electrochemical techniques have been used to determine the binding constant, Kb and the linear Stern–Volmer quenching constant, KSV. The results indicate that the ruthenium(II) complexes interact with CT-DNA strongly in a groove binding mode. The interactions of bovine serum albumin (BSA) with the complexes were also investigated with the help of absorption and fluorescence spectroscopy tools. Absorption spectroscopy proved the formation of a ground state BSA-[Ru(L)(bpy)2](ClO4)2 complex. The antibacterial study showed that the Ru(II) complexes (1 and 2) have better activity than the standard antibiotics but weak activity than the ligands. 相似文献
7.
The kinetics of the complex-formation reactions between monofunctional palladium(II) complexes [Pd(NNN)Cl]+, where NNN is 2,2′:6′,2″-terpyridine (terpy), diethylenetriamine (dien) or bis(2-pyridylmethyl)amine (bpma), with pyridine, 4-methylpyridine, 4-acetylpyridine, 4-cyanopyridine and 4-aminopyridine, have been studied in methanol at 25 °C using stopped-flow spectrophotometry. The highest reactivity was observed for the [Pd(terpy)Cl]+ complex, whereas 4-aminopyridine is the strongest nucleophile. The results, compared with those previously published on the [Pt(NNN)Cl]+ complexes, are discussed in terms of reactivity and discrimination ability of the reaction centre. The crystal structure of [Pd(terpy)(py)](ClO4)2 has been determined by X-ray diffraction. Crystals are triclinic, space group , and consist of distorted square planar [Pd(terpy)(py)]2+ cations and perchlorate anions. The Pd-N bond length to the central atom of terpy ligand is well below 2.0 Å and significantly shorter than any of the other M-N distances. The pyridine plane forms a dihedral angle of 61.9(2)° with the coordination N4 donors. 相似文献
8.
Pyrazole-3,5-dicarboxylate-bridged dinuclear ruthenium(II) and osmium(II) complexes of 2,2′-bipyridine of composition [(bpy)2Ru(pzdc)Ru(bpy)2](ClO4) · H2O (1) and [(bpy)2Os(pzdc)Os(bpy)2](ClO4) · H2O (2) have been obtained in high yield and have been separated to their homochiral (ΛΛ/ΔΔ) rac (1a, 2a) and heterochiral (ΛΔ/ΔΛ) meso (1b, 2b) diastereoisomers. The distinctive structural features of these diastereoisomers have been characterized by 1-D and 2-D 1H NMR spectroscopy. The X-ray crystal structure of rac-[(bpy)2Os(pzdc)Os(bpy)2](ClO4) · H2O (2a) has been determined. The electrochemical and electronic spectral studies have established that there remain difference in properties and hence difference in intermetallic communication between the diastereoisomeric forms in each case. 相似文献
9.
Cristian Enachescu Itana Krivokapic Jose Antonio Real Andreas Hauser 《Inorganica chimica acta》2007,360(13):3945-3950
The spin transition of the [Co(terpy)2]2+ complex (terpy = 2,2′:6′,2″-terpyridine) is analysed based on experimental data from optical spectroscopy and magnetic susceptibility measurements. The single crystal absorption spectrum of [Co(terpy)2](ClO4)2 shows an asymmetric absorption band at 14 400 cm−1 with an intensity typical for a spin-allowed d-d transition and a temperature behaviour typical for a thermal spin transition. The single crystal absorption spectra of suggest that in this compound, the complex is essentially in the high-spin state at all temperatures. However, the increase in intensity observed in the region of the low-spin MLCT transition with increasing temperature implies an unusual partial thermal population of the low-spin state of up to about 10% at room temperature. Finally, high-spin → low-spin relaxation curves following pulsed laser excitation for [Co(terpy)2](ClO4)2 dispersed in KBr discs, and as a comparison for the closely related [Co(4-terpyridone)2](ClO4)2 spin-crossover compound are given. 相似文献
10.
11.
Saija LuukkanenMatti Haukka Olli LaineTapani Venäläinen Pirjo VainiotaloTapani A Pakkanen 《Inorganica chimica acta》2002,332(1):25-29
Chlorine containing ruthenium bipyridine carbonyl compounds react readily in dilute alkaline solutions under a CO atmosphere affording a poorly soluble and air sensitive product that is suggested to have a polymeric nature. Various analysis methods (MS and TPD) were used in the characterisation of the product. The replacement of the axial chloride ligands in trans(Cl), cis(CO)[Ru(bpy)(CO)2Cl2] and [Ru(bpy)(CO)2Cl]2 is proposed to be the initial step in the polymerisation. The replacement of chlorides in methanolic solution was confirmed by isolating and characterising the dimeric intermediate [Ru(bpy)(CO)2(COOCH3)]2. 相似文献
12.
《Inorganica chimica acta》1988,148(1):97-100
Six photoproducts were observed in the photolysis of [Ru(bpy)3]2+ in N,N-dimethylformamide (DMF) in the presence of chloride ions. The primary products were cis-[Ru(bpy)2Cl2] and cis-[Ru(bpy)2-(DMF)Cl]+. The remaining ruthenium products, which were thermally unstable to varying degrees, were cis-[Ru(bpy)2Cl2]+, [Ru(bpy)3]+, and a binuclear species we have tentatively identified as [Ru(bpy)2Cl]2n+ (n = 3 or 4). 相似文献
13.
The reaction of ruthenium carbonyl polymer ([Ru(CO)2Cl2]n) with azopyridyl compounds (2,2′-azobispyridine; apy or 2-phenylazopyridine; pap) generated new complexes, [Ru(azo)(CO)2Cl2] (azo = apy, pap). [Ru(apy)(CO)2Cl2] underwent photodecarbonylation to give a chloro-bridged dimer complex, whereas the corresponding pap complex ([Ru(pap)(CO)2Cl2]) was not converted to a dimer. The reactions of the chloro-bridged dimer containing the bpy ligand (bpy = 2,2′-bipyridine) with either apy or pap resulted in the formation of mixed polypyridyl complexes, [Ru(azo)(bpy)(CO)Cl]+. The novel complexes containing azo ligands were characterized by various spectroscopic measurements including the determination of X-ray crystallographic structures. Both [Ru(azo)(CO)2Cl2] complexes have two CO groups in a cis position to each other and two chlorides in a trans position. The azo groups are situated cis to the CO ligand in [Ru(azo)(bpy)(CO)Cl]+. All complexes have azo N-N bond lengths of 1.26-1.29 Å. The complexes exhibited azo-based two-electron reduction processes in electrochemical measurements. The effects of introducing azopyridyl ligands to the ruthenium carbonyl complexes were examined by ligand-based redox potentials, stretching frequencies and force constants of CO groups and bond parameters around Ru-CO moieties. 相似文献
14.
Susanne Mossin Henning Osholm Sørensen Høgni Weihe Inger Søtofte 《Inorganica chimica acta》2005,358(4):1096-1106
The syntheses, structures and magnetic properties of five new manganese (III) cyclam complexes, trans-[Mn(cyclam)(OH2)2](CF3SO3)3 · H2O, trans-[Mn(cyclam)I2]I, trans-[Mn(cyclam)(ONO)2]ClO4, trans-[Mn(cyclam)(OClO3)2]ClO4 and trans-[Mn(cyclam)(CH3COO)(CH3COOH)](ClO4)2, are reported. Cyclam is the tetradentate amine ligand 1,4,8,11-tetraazacyclotetradecane. The complexes all exhibit pronounced tetragonal elongation of the coordination octahedron with the four cyclam nitrogens occupying the four equatorial positions. The magnetic properties are consistent with the formulation of the complexes as high-spin d4 systems. trans-[Mn(cyclam)(OH2)2](CF3SO3)3 · H2O is shown to be a convenient starting material for the syntheses of trans cyclam complexes. [Mn(cyclam)(CH3COO)(CH3COOH)](ClO4)2 exhibits extremely short intermolecular hydrogen bonds resulting in a pseudo-chain structure. The tilt of the axial ligands with respect to the equatorial plane containing the manganese and the cyclam nitrogen atoms is discussed. 相似文献
15.
Ennio Zangrando 《Inorganica chimica acta》2009,362(3):820-60
The preparation and structural characterization of several new Ru(II) complexes in which four coordination positions are occupied by the sulfur atoms of a macrocycle, either 1,4,7,10-tetrathiacyclododecane ([12]aneS4) or 1,5,9,13-tetrathiacyclohexadecane ([16]aneS4), and the two others by relatively labile ligands (Cl−, , H2O, dmso-S), are described:cis-[Ru([12]aneS4)(dmso-S)(H2O)](CF3SO3)2 (2a), cis-[Ru([12]aneS4)(dmso-S)(ONO2)](NO3) (2b), cis-[Ru([16]aneS4)Cl2] (4), and trans-[Ru([16]aneS4)(dmso-S)(H2O)](CF3SO3)2 (5).The complexes of the larger [16]aneS4 macrocycle have a flexible coordination geometry, either cis or trans, that makes them unsuited for being used as precursors in metal-driven self-assembly processes.On the contrary, the [12]aneS4 complexes cis-[Ru([12]aneS4)(dmso-S)Cl]Cl (1) and, above all, its chlorido free derivatives cis-[Ru([12]aneS4)(dmso-S)(H2O)](CF3SO3)2 (2a) and cis-[Ru([12]aneS4)(dmso-S)(ONO2)](NO3) (2b) are potential precursors of the geometrically stable 90° bis-acceptor fragment cis-[Ru([12]aneS4)]2+.Preliminary results of their reactivity towards the linear linker pyrazine (pyz) showed that the nature of the isolated product depends on that of the counter-anion.When treated with pyz 2b afforded the dinuclear complex [{Ru([12]aneS4)(ONO2)}2(μ-pyz)](NO3)2 (8), while 2a gave the molecular triangle [{cis-Ru([12]aneS4)(μ-pyz)}3](CF3SO3)6 (9), both in low yields.The X-ray structures of compounds 2a, 2b, 4, 5, [{Ru([12]aneS4)Cl}2(μ-pyz)]Cl2 (7), 9, and of the sandwich complex[Ru([12]aneS3-S)2](CF3SO3)2 (3), in which only three sulfur atoms of each macrocycle are bound to ruthenium, are also described. 相似文献
16.
Katerina N. Lazarou Aris Terzis Catherine P. Raptopoulou 《Inorganica chimica acta》2010,363(1):107-2622
The use of succinamic acid (H2sucm) in Cu(ClO4)2·6H2O/N,N′-donor [2,2′-bipyridine (bpy), 1,10-phenanthroline (phen), 4,4′-dimethyl-2,2′-bipyridine (dmbpy), 4,4′-bipyridine (4,4′-bpy)] reaction mixtures yielded compounds [Cu2(Hsucm)3(bpy)2](ClO4)·0.5MeOH (1·0.5MeOH), [Cu2(Hsucm)(OH)(H2O)(bpy)](ClO4)2 (2), [Cu4(Hsucm)5(dmbpy)4]n(ClO4)3n·nH2O ·0.53nMeOH (3·nH2O·0.53nMeOH), [Cu2(Hsucm)2(dmbpy)2(H2O)2](ClO4)2·2H2O (4·2H2O), [Cu2(Hsucm)2(phen)2(H2O)2](ClO4)2·1.8MeOH (5·1.8MeOH), [Cu2(Hsucm)2(phen)2(MeOH)2](ClO4)2·MeOH (6·MeOH) and [Cu(Hsucm)2(H2O)(4,4′-bpy)]n (7). The succinamate(−1) ligand exists in five different coordination modes in the structures of 1-7, i.e. the common syn, syn μ2-κO:κO′ in 1-6, the μ2-κ2O in 1, the μ2-κ2O:κO′ in 1, the μ3-κ2O:κ2O′ in 3, and the monodentate κO in 7. The primary amide group of Hsucm− remains uncoordinated and participates in intra- and intermolecular hydrogen bonding interactions leading to interesting crystal structures. Characteristic IR bands of the complexes are discussed in terms of the known structures and the coordination modes of the Hsucm− ligands. The thermal decomposition of representative complexes was monitored by TG/DTG and DTA measurements. 相似文献
17.
Three new complexes [Pt(dpop)(Cl)2], [(Cl)2Pt(dpop)Pt(Cl)2] and [(bpy)2Ru(dpop)Pt(Cl)2](PF6)2 (dpop = dipyrido(2,3-a:3′,2′-h)phenazine) were prepared and studied. The electronic absorption spectra of the complexes display Pt dπ → dpop π* and Ru dπ → dpop π* MLCT transitions at longer wavelengths than for previously reported similar complexes. Results of cyclic voltammograms show reversible dpop centered reductions while for the mixed metal [(bpy)2Ru(dpop)Pt(Cl)2]2+ an irreversible Pt(II) oxidative wave precedes the Ru(II) oxidation/reduction couple. Spectroelectrochemical results show that all oxidative and reductive processes are completely reversible. The [(Cl)2Pt(dpop)Pt(Cl)2] complex cleaves in solution with pseudo-first order kinetics resulting in loss of the Pt dπ → dpop π* MLCT transition at 545 nm. 相似文献
18.
Two new ruthenium complexes [Ru(bpy)2(mitatp)](ClO4)21 and [Ru(bpy)2(nitatp)](ClO4)22 (bpy = 2,2′-bipyridine, mitatp = 5-methoxy-isatino[1,2-b]-1,4,8,9-tetraazatriphenylene, nitatp = 5-nitro-isatino[1,2-b]-1,4,8,9-tetraazatriphenylene) have been synthesized and characterized by elemental analysis, 1H NMR, mass spectrometry and cyclic voltammetry. Spectroscopic and viscosity measurements proved that the two Ru(II) complexes intercalate DNA with larger binding constants than that of [Ru(bpy)2(dppz)]2+ (dppz = dipyrido[3,2-a:2′,3′-c]phenazine) and possess the excited lifetime of microsecond scale upon binding to DNA. Both complexes can efficiently photocleave pBR322 DNA in vitro under irradiation. Singlet oxygen (1O2) was proved to contribute to the DNA photocleavage process, the 1O2 quantum yields was determined to be 0.43 and 0.36 for 1 and 2, respectively. Moreover, a photoinduced electron transfer mechanism was also found to be involved in the DNA cleavage process. 相似文献
19.
Jack M. Harrowfield Brian W. Skelton Allan H. White Faye R. Wilner 《Inorganica chimica acta》2004,357(8):2358-2364
Structure determinations for the lanthanide (Ln) complexes [(CH3)2NH2][Gd(dmf)8](ClO4)4, [Tb(dmf)8](ClO4)3 and [Ho(dmf)7(OH2)](ClO4)3 (dmf=N,N-dimethylformamide) show all three to contain an LnO8 coordination unit of essentially square-antiprismatic geometry. The geometry of the inner coordination sphere appears to be little perturbed by quite major differences in the lattice environment of the cations. Attractive interactions between coordinated dmf molecules may be one contributor to the stability of the primary coordination sphere. 相似文献
20.
Take-aki Koizumi 《Inorganica chimica acta》2008,361(7):2131-2138
The molecular structure of an o-phenylenediamine unit-containing oligophenylene (1), Ph-Ph′-Ph′(2,3-NH2)-Ph′-Ph (Ph = phenyl; Ph′ = p-phenylene; Ph′(2,3-NH2) = 2,3-diamino-p-phenylene), was determined by X-ray crystallography. 1 has a twisted structure, and forms an intermolecular C-H?π interaction network. The -NH2 group of 1 was air-oxidized to an imine, NH, group in the presence of [RuCl2(bpy)2] (bpy = 2,2′-bipyridyl) and gave a ruthenium(II)-benzoquinone diimine complex [Ru(2)(bpy)2](PF6)2 (2: Ph-Ph′-Ph′(2,3-imine)-Ph′-Ph). The molecular structure of [Ru(2)(bpy)2](PF6)2 was confirmed by X-ray crystallography. [Ru(2)(bpy)2](PF6)2 underwent two-step electrochemical reduction with E1/2 = −0.889 V and −1.531 V versus Fc+/Fc. The E1/2’s were located at higher potentials by 91 mV and 117 mV, respectively, than those of reported [Ru(bqdi)(bpy)2](PF6)2 (bqdi = benzoquinone diimine). Electrochemical oxidation of [Ru(2)(bpy)2](PF6)2 occurred at a lower potential by 180 mV than that of [Ru(bqdi)(bpy)2](PF6)2. Occurrence of the easier reduction and oxidation of [Ru(2)(bpy)2](PF6)2 than those of [Ru(bqdi)(bpy)2](PF6)2 is ascribed to the presence of a large π-conjugation system in 2. 相似文献