Theoretical exploration of uranyl complexes of a designed polypyrrolic macrocycle: structure/property effects of hinge size on Pacman-shaped complexes

A polypyrrolic macrocycle with naphthalenyl linkers between the N(4)-donor compartments (L(2)) was designed theoretically according to its experimentally-known analogues with phenylenyl (L(1)) and anthracenyl (L(3)) linkers. The uranyl and bis(uranyl) complexes formed by this L(2) ligand have been examined using scalar-relativistic density functional theory. The calculated structural properties of the mononuclear uranyl-L(2) complexes are similar to those of their L(1) counterparts. The binuclear L(2) complexes exhibit a butterfly-like bis(uranyl) core in which a linear uranyl is coordinated in a side-by-side fashion to a cis-uranyl unit. The calculated U[double bond, length as m-dash]O bond orders in the uranyl-L(2) complexes indicate partial triple bonding character with the only exceptions being the U-O(endo) bonds in the U(2)O(4) core of the butterfly-shaped binuclear complexes. Overall, the bond orders agree with the trends in the calculated U[double bond, length as m-dash]O stretching vibrational frequencies. Regarding the bis(uranyl) L(1), L(2) and L(3) complexes, the phenylenyl-hinge L(1) complexes adopt a butterfly-like and a T-shaped isomer in the oxidation state of U(vi), but only a butterfly-like one in the U(v), which differs from that of the naphthalenyl-hinge L(2) complexes as well as the lateral twisted structure of the anthracenyl-hinge L(3) complexes. The intramolecular cation-cation interactions are found in the L(1) and L(2) complexes, but are absent in the L(3) complexes. Finally, using model uranyl transfer reactions from the L(1) complexes, the formation of the mononuclear L(2) complexes is calculated to be a slightly endothermic process. This suggests that it should be possible to synthesize the L(2) complexes using similar protocols as employed for the L(1) complexes.     

α-氨基酸乙酯卤根合铂(II)的合成和构型研究

Sixteen new halogenoethylaminoacidato Pt(II) complexes were synthesized and characterized, of which eightiodo complexes (PtA2I2) (A = DL-a-AlaOEt, L-a-alaOEt, DL-a-PheOEt, L-a-PheOEt, DI-A-AspOEt, L-a-AspOEt, DL-a-SerOEt and L-a-Lys OEt), four chloro compounds (PtA2Cl2)(A = DL-a-PheOEt, DL-a-AspOEt, L-a-Asp OEt) and (DL-a-PheHOEt)2(PtCl4) were obtained by reaction of K2 (PtX4)(X = I^-, Cl^-) with the corresponding ethylaminoacidates in water. The other chlorethylaminoacidato Pt(II) complexes (PtA2Cl2) (A = DL-a-AlaOEt, L-a-AlaOEt, L-a-PheOEt, DL-a-Ser OEt) were synthesized in acetone by exchange reaction of the corresponding iodo complexes with AgCl in order to avoid hydrolysis of the ethyl aminoacidates. Molar conductivity determination showed that all the Pt(II) complexes obtained were neutral molecules with the exception of (DL-a-PheHOEt)2(PtCl4) which existed as an anion. As shown by diole moment determination and modified thiourea reaction, iodo complexes 1-7 and some of the chloro complexes (PtA2Cl2) (A = DL-a-alaOEt, D-a-AlaOEt, DL-a-SerOEt) were of cis-configuration and the other chloro complexes were of trans-configuration.     

Trans titanium(IV) complexes of salen ligands exhibit high antitumor activity

Salen-titanium(IV) complexes are introduced as a new family of highly efficient antitumor complexes, being the first cytotoxic titanium(IV) complexes of trans labile ligands, as characterized crystallographically. Four complexes with different aromatic substitutions were analyzed, reveling a meaningful effect of the ligand structure on the complex performance. All complexes exhibit high hydrolytic stability, where the labile OAr ligands hydrolyze in a 10% D(2)O solution with t(1/2) ranging from 2 to 11 h. The IC(50) values obtained for three of the salen complexes studied on HT-29 colon and OVCAR-1 ovarian cells demonstrate activity that exceeds those of the known tianium(IV) complexes Cp(2)TiCl(2) and (bzac)(2)Ti(OiPr)(2) and that of cisplatin, where the most active para-chlorinated complex exhibits activity enhancement relative to cisplatin by 10-fold.     

Platinum complexes of diazo ligands. Studies of regioselective aromatic ring amination, oxidative halogen addition and reductive halogen elimination reactions

2-(Arylazo)pyridine ligands, L1a-1c react with the salt K2[PtCl4] to give the mononuclear complexes [PtCl2(L1)](1), which readily react with ArNH2 to yield the monochloro complexes of type [PtCl(L2)](HL2= 2-[(2-(arylamino)phenyl)azo]pyridine)(2) via regioselective ortho-amine fusion at the pendent aryl ring of coordinated L1. Oxidative addition of the electrophiles Y2(Y = Cl, Br, I) to the square-planar platinum(II) complex, has led to syntheses of the corresponding octahedral platinum(IV) complexes, [PtY3(L2)](3) in high yields. Ascorbate ion reductions of the platinum(IV) complexes, , resulted in reductive halogen elimination to revert to the platinum(II) complexes almost quantitatively. Isolation of products and X-ray structure determination of the representative complexes followed all these chemical reactions. In crystal packing, the compound [PtCl2(L1c)](1c) forms dimeric units with a Pt...Pt distance of 3.699(1) A. In contrast, the crystal packing of 2b revealed that the molecules are arranged in an antiparallel fashion to form a noncovalent 1D chain to accommodate pi(aryl)-pi(pyridyl) and Pt-pi(aryl) interactions. Notably, the oxidation of [Pt(II)Cl(L2a)](2a) by I2 produced a mixed halide complex [Pt(IV)ClI2(L2a)](5), which, in turn, is reduced by ascorbate ion to produce [Pt(II)I(L2a)] with the elimination of ClI. All the platinum(II) complexes are brown, the platinum(IV) complexes, on the other hand, are green. Low-energy visible range transitions in the complexes of the extended ligand [L2]- are ascribed to ligand basedpi-pi* transitions. Cyclic voltammetric behaviour of the complexes is reported.     

Anticancer activity, attenuation on the absorption of calcium in mitochondria, and catalase activity for manganese complexes of N-substituted di(picolyl)amine

In order to find multifunction anticancer complexes, three Mn(II) complexes of N-substituted di(2-pyridylmethyl)amine were characterized and used as agents to interfere with the functions of mitochondria and the metabolite of O(2) in cancer cells. It was found that carboxylate-bridged dimanganese(II) systems are good models of catalase and exhibit good inhibition of the proliferation of U251 and HeLa cells. The inhibiting activity of these manganese(II) complexes on the tumor cells in vitro was related to their disproportionating H(2)O(2) activity. The reaction of carboxylate-bridged dimanganese Mn(II) complex with H(2)O(2) forms a stable Mn(III)-(μ-O)(2)-Mn(IV) complex. Extensive experimental results show that chloride-bridged dimanganese(II) complexes could inhibit the swelling of calcium(II) overloaded mitochondria, and carboxylate-bridged manganese(II) complexes enhance the swelling of calcium(II) overloaded mitochondria. These results indicate that the interactions between Mn(II) complexes of N-substituted di(picolyl)amine and mitochondria are influenced by the structure and conformation of the complexes. Mn(II) complexes of N-substituted di(picolyl)amine could be developed as multifunctional anticancer complexes to interfere with the absorption of calcium(II) in mitochondria and the metabolite of O(2) through the H(2)O(2) or ROS involved signaling induced apoptosis of cancer cells.     

Electronic, epr and magnetic studies of Co(II), Ni(II) and Cu(II) complexes with thiosemicarbazone (L1) and semicarbazone (L2) derived from pyrole-2-carboxyaldehyde

Co(II), Ni(II) and Cu(II) complexes are synthesized with thiosemicarbazone (L(1)) and semicarbazone (L(2)) derived from pyrole-2-carboxyaldehyde. These complexes are characterized by elemental analysis, molar conductance, magnetic susceptibility measurements, mass, IR, electronic and EPR spectral studies .The molar conductance measurements of the complexes in DMSO correspond to non-electrolytic nature except Co(L1)2(NO3)2 and Ni(L1)2(NO3)2 complexes which are 1:2 electrolytes. All the complexes are of high-spin type. On the basis of spectral studies an octahedral geometry may be assigned for Co(II) and Ni(II) complexes except Co(L1)2(NO3)2 and Ni(L1)2(NO3)2 which are of tetrahedral geometry. A tetragonal geometry may be suggested for Cu(II) complexes.     

Synthesis and characterization of phosphorescent cyclometalated iridium complexes

The preparation, photophysics, and solid state structures of octahedral organometallic Ir complexes with several different cyclometalated ligands are reported. IrCl3.nH2O cleanly cyclometalates a number of different compounds (i.e., 2-phenylpyridine, 2-(p-tolyl)pyridine, benzoquinoline, 2-phenylbenzothiazole, 2-(1-naphthyl)benzothiazole, and 2-phenylquinoline), forming the corresponding chloride-bridged dimers, CwedgeN2Ir(mu-Cl)2IrCwedgeN2 (CwedgeNis a cyclometalated ligand) in good yield. These chloride-bridged dimers react with acetyl acetone (acacH) and other bidentate, monoanionic ligands such as picolinic acid (picH) and N-methylsalicylimine (salH), to give monomeric CwedgeN2Ir(LX) complexes (LX = acac, pic, sal). The emission spectra of these complexes are largely governed by the nature of the cyclometalating ligand, leading to lambda(max) values from 510 to 606 nm for the complexes reported here. The strong spin-orbit coupling of iridium mixes the formally forbidden 3MLCT and 3pi-pi* transitions with the allowed 1MLCT, leading to a strong phosphorescence with good quantum efficiencies (0.1-0.4) and room temperature lifetimes in the microsecond regime. The emission spectra of the CwedgeN2Ir(LX) complexes are surprisingly similar to the fac-IrCwedgeN3 complex of the same ligand, even though the structures of the two complexes are markedly different. The crystal structures of two of the CwedgeN2Ir(acac) complexes (i.e., CwedgeN = ppy and tpy) have been determined. Both complexes show cis-C,C', trans-N,N' disposition of the two cyclometalated ligands, similar to the structures reported for other complexes with a "CwedgeN2Ir" fragment. NMR data (1H and 13C) support a similar structure for all of the CwedgeN2Ir(LX) complexes. Close intermolecular contacts in both (ppy)2Ir(acac) and (tpy)2Ir(acac) lead to significantly red shifted emission spectra for crystalline samples of the ppy and tpy complexes relative to their solution spectra.     

新型双核配合物的形成、与DNA的作用机制及荧光性质研究

利用紫外、荧光和粘度等方法研究了含不同配体的钌(II)配合物[Ru(phen)₂CImP]^2＋(CImP＝3,4-二羟基-咪唑并[4,5-i][1,10]邻菲咯啉)和[Ru(phen)₂TPPZ]^2＋(TPPZ＝四吡啶[3,2-a:2',3'-c:3',2'-h:2',3'-j]吩嗪)与DNA的作用机制, 并研究了配合物与Zn^2＋配合后荧光性质变化. 结果表明[Ru(phen)₂TPPZ]^2＋与DNA以插入模式作用, 而[Ru(phen)₂CImP]^2＋与DNA则以沟面结合模式作用. 向配合物溶液中滴加Zn^2＋后, 配合物[Ru(phen)₂TPPZ]^2＋和[Ru(phen)₂CImP]^2＋均可以与Zn^2＋形成双核配合物[Ru(phen)₂(TPPZ)Zn]^4＋和[Ru(phen)₂(CImP)Zn]^4＋, 配合物的荧光减弱. 与DNA作用后, 配合物仍可以与Zn^2＋配位形成双核配合物, 但[Ru(phen)₂(TPPZ)Zn]^4＋保持插入模式与DNA作用, 配合物的荧光减弱. 而[Ru(phen)₂(CImP)Zn]^4＋与DNA则由沟面结合改为插入结合, 配合物的荧光增强.     

First raw transition metal complexes of salicylidene and 2-hydroxy-1-naphthylidene-N-cyanoacetohydrazone

Mn(II), Co(II), Ni(II), Cu(II) and Zn(II) complexes of salicylidene-N-cyano-acetohydrazone H2L1 and 2-hydroxy-l-naphthylidene-N-cyanoacetohydrazone H2L2 have been prepared in ethanolic solution and characterized by analytical, spectral, magnetic susceptibility, molar conductivity and TGA measurements. The analytical data show that all the complexes derived from H2L1 and H2L2 are formed in molar ratios 1M:2L, except the complexes of Mn(II), Co(II) and Cu(II) acetates of H2L2 and the complexes of Mn(II), Co(II) and Ni(II) acetates and CuCl2 of H2L1 are formed in 1:1 molar ratios. The conductance data show that all metal complexes are non-electrolytes. Electronic absorption spectra and magnetic susceptibility measurements proved that the prepared complexes have octahedral configuration except [Co(HL2)OAc] which has tetrahedral structure. The ligand field parameters were calculated for the Co(II) and Ni(II) complexes and the data show that the covalent character of the metal ligand sigma-bond is low. The ESR parameters of the Cu(II) complexes at room temperature were calculated. Thermal TGA for some solid complexes are reported.     

A gas- and condensed-phase density functional study of donor-acceptor complexes of sulfur trioxide

A series of donor-acceptor complexes containing sulfur trioxide have been studied in the gas and condensed phases using density functional theory. The condensed phase is represented using the polarizable continuum model. The systems investigated include complexes of nitrogen-containing donor molecules, (CH(3))(n)H(3-n)N (n = 0-3), with SO(3) and complexes of oxygen-containing donor molecules, (CH(3))(m)H(2-m)O (m = 0-2), with SO(3). Significant differences are observed between the gas- and condensed-phase properties of the complexes as a result of the ability of the condensed-phase medium to support higher charge separation between the donor and acceptor. The gas/condensed-phase behavior of two nitrogen-containing complexes, (CH(3))H(2)N-SO(3) and (CH(3))(2)HN-SO(3), has been investigated for the first time. These complexes exhibit properties intermediate to the previously observed H(3)N-SO(3) and (CH(3))(3)N-SO(3) complexes. Systematic trends in the gas- and condensed-phase structure and properties have been observed as methyl groups are added to the donor molecule. In addition, two oxygen-containing complexes, CH(3)OH-SO(3) and (CH(3))(2)O-SO(3), have been characterized for the first time. The differences between the gas- and condensed-phase properties of the oxygen-containing complexes are, in many cases, larger than those of the nitrogen-containing complexes, and therefore they represent an intriguing new class of complexes for potential experimental observation. Finally, a strong correlation between the charge transfer and binding energy has been obtained for both the nitrogen- and oxygen-containing complexes of sulfur trioxide.     

pi-Bonding in complexes of benzannulated biscarbenes, -germylenes, and -stannylenes: an experimental and theoretical study

Benzannulated bisstannylenes, exhibiting a CH(2)C(CH(3))(2)CH(2) linking unit and CH(2)tBu (1) or CH(2)CH(2)CH(2)NMe(2) (2) N-substituents, and their molybdenum tetacarbonyl complexes 3 and 4 have been prepared. The complexes 3 and 4 exhibit remarkably short Mo-E bond lengths compared to the related biscarbene and bisgermylene complexes. The experimentally determined bonding parameters of the molybdenum bisstannylene complexes are discussed based on DFT calculations.     

Solution behavior and structural diversity of bis(dialkylphosphino)methane complexes of palladium

The preparation of dipalladium complexes containing sterically nondemanding diphosphine (P-P) ligands of the type R(2)PCH(2)PR(2) where R = Me (dmpm) or Et (depm) is reported. Variable-temperature (1)H NMR spectra of the Pd(I)(2) complexes Pd(2)X(2)(dmpm)(2) (X = Cl, Br, or I; the P-P ligands in the Pd(2) complexes are always bridged, but for convenience, the micro -symbol is omitted) show the complexes to be fluxional in solution, the barriers to a ring-flipping process being DeltaG( double dagger ) = 37.9, 39.0, and 43.2 +/- 0.9 kJ mol(-)(1) for the chloro, bromo, and iodo complexes, respectively. Treatment of Pd(2)X(2)(P-P)(2) (X = Cl or Br) with X(2) generates the stable, face-to-face Pd(II)(2) derivatives trans-Pd(2)X(4)(P-P)(2), while oxidation of Pd(2)I(2)(P-P)(2) complexes with I(2) generates a new type of symmetrically di-iodo-bridged, five-coordinate complexes Pd(2)I(2)(micro -I)(2)(dmpm)(2) and Pd(2)I(2)(micro -I)(2)(depm)(2). The molecular crystal structures of four dipalladium(II) complexes are described: trans-Pd(2)Cl(4)(dmpm)(2).2CHCl(3), trans-Pd(2)Br(4)(dmpm)(2), trans-Pd(2)Cl(4)(depm)(2), and Pd(2)I(2)(micro -I)(2)(dmpm)(2). Solution NMR and UV-vis absorption spectra are consistent with the solid-state structures determined by X-ray diffraction. The stability of the dimeric Pd(II) complexes is attributed primarily to ligand steric factors.     

The unique chemistry of platina-beta-diketones

This review presents syntheses, structures and the reactivity of platina-beta-diketones [Pt2{(COR)2H}2(mu-Cl)2] (R = alkyl, omega-phenylalkyl), being the first electronically unsaturated (16 ve; ve-valence electrons) and kinetically labile metalla-beta-diketones. They were found to react with amines, yielding platina-beta-diketonates of platina-beta-diketones having Pt(4) zigzag chains analogous to platinum blue complexes. Reactions of platina-beta-diketones with monodentate and bidentate N-, P-, As-, O-, and S-donor ligands are described resulting in the formation of acyl(hydrido)platinum(IV) complexes, acyl(chloro)platinum(II) complexes, platinum complexes having enamine-amide type ligands, and of platinum(II) complexes with cyclic aminocarbene ligands, respectively. These reactions are discussed in terms of oxidative addition and reductive elimination reactions showing that platina-beta-diketones react as hydroxycarbene complexes whose OH groups are intramolecularly hydrogen-bridged to acyl ligands. Furthermore, the synthesis and structures of dinuclear platinum(II) complexes with bridging mu-acyl(hydroxycarbene) ligands are presented.     

Magnetic, electronic and electrochemical studies of mono and binuclear Cu(II) complexes using novel macrocyclic ligands

A series of new mono and binuclear copper (II) complexes [Cul]X(2)and [Cu(2)lX(2)] where 1 = L(1), L(2) and L(3) are the macrocyclic ligands. In mononuclear complexes the geometry of Cu(II) ion is distorted squareplanar and in binuclear complexes the geometry of Cu(II) is tetragonal. The synthesized complexes were characterized by spectroscopic (IR,UV-vis and ESR) techniques. Electrochemical studies of the complexes reveals that all the mononuclear Cu(II) complexes show a single quasireversible one-electron transfer reduction wave (E(pc) = -0.76 to -0.84V) and the binuclear complexes show two quasireversible one electron transfer reduction waves (E(pc)(1) = -0.86 to -1.01V, E(pc)(2) = -1.11 to -1.43V) in cathodic region. The ESR spectra of mononuclear complexes show four lines with nuclear hyperfine splittings with the observed g(11) values in the ranges 2.20-2.28, g( perpendicular) = 2.01-2.06 and A(11) = 125-273. The binuclear complexes show a broad ESR spectra with g = 2.10-2.11. The room temperature magnetic moment values for the mononuclear complexes are in the range [mu(eff) = 1.70-1.72BM] and for the binuclear complexes the range is [mu(eff) = 1.46-1.59BM].     

Novel supramolecular assembly of symmetrical mixed-metal-ligand complexes of dioxouranium(VI)

Some binary and ternary novel complexes of dioxouranium(VI) with 8-hydroxy-7-quinolinecarboxaldehyde (OXH) have been prepared and characterized by elemental analyses, magnetic susceptibility measurements and spectral studies. Coordination effects on the vibrational spectra of the ligands have been investigated. The amine exchange reactions of coordinated Schiff bases in these complexes have been also studied, which reveal symmetrical tetradentate Schiff base complexes. Metal exchange reaction of dioxouranium(VI) complexes was obtained when reacted with tetradentate Schiff base complexes of Cu(II) with ZrCl(4)/UO(2)(CH(3)COO)(2) giving heterobinuclear complexes. Magnetic, electronic and IR spectral data suggest the configurations of distorted square planar ligand field copper(II) complexes. The ligands behave as bi-(O,O) and tetradentate (N(2),O(2)) donors. El-Sonbati equation has been used to evaluate the symmetric stretching frequency from which the F(U-O) and F(UO,UO)(-) were calculated. The bond distances of these complexes were also investigated.     

New insights into the visible-light-induced DNA cleavage activity of dipyridoquinoxaline complexes of bivalent 3d-metal ions

Dipyridoquinoxaline (dpq) complexes of bivalent 3d-metal ions, viz., [FeII(dpq)3](PF6)2 (1), [CoII(dpq)3](ClO4)2 (2), [NiII(dpq)3](ClO4)2 (3), [CuII(dpq)2(H2O)](ClO4)2 (4), [ZnII(dpq)3](ClO4)2 (5), and [ZnII(dpq)2(DMF)2](ClO4)2 (5a) (DMF = N,N-dimethylformamide), are prepared and their photoinduced DNA cleavage activity studied. Structural characterization for the complexes 1 and 5a is done by single-crystal X-ray crystallography. All the complexes show efficient binding propensity to calf thymus DNA with a binding constant (K) value of approximately 10(5) M(-1). Complexes 1, 2, and 4 show metal-based cyclic voltammetric responses at 1.2, 0.4, and 0.09 V (vs SCE) in DMF 0.1 M [Bun4N](ClO4) assignable to the respective FeIII/FeII, CoIII/CoII, and CuII/CuI couples. The NiII and ZnII complexes do not show any metal-based redox process. The dpq-based reductions are observed in the potential range of -1.0 to -1.7 V vs SCE. DNA melting and viscosity data indicate the groove-binding nature of the complexes. Control experiments using distamycin-A suggest a minor groove-binding propensity of the complexes. The complexes exhibit photoinduced cleavage of supercoiled pUC19 DNA in UV light of 365 nm. The diamagnetic d6-FeII and d10-ZnII complexes are cleavage-inactive on irradiation with visible light. The paramagnetic d7-CoII and d9-CuII complexes exhibit efficient DNA cleavage activity on photoirradiation at their respective d-d band. The paramagnetic d8-NiII complex displays only minor DNA cleavage activity on irradiation at its d-d band. The DNA cleavage reactions at visible light under aerobic conditions involve the formation of hydroxyl radical. The CoII complex shows photocleavage of DNA under an argon atmosphere. Theoretical calculations on the complexes suggest a photoredox pathway in preference to a type-2 process forming singlet oxygen for the visible-light-induced DNA cleavage activity of the 3d-metal complexes. The theoretical data also predict that the photoredox pathway is favorable for the 3d7-CoII and 3d9-CuII complexes to exhibit DNA cleavage activity, while the analogous 3d6-FeII and 3d8-NiII complexes are energetically unfavorable for the exhibition of such activity under visible light. The CoII and CuII complexes are better suited for designing and developing new metal-based PDT agents than their cleavage-inactive FeII, NiII, and ZnII analogues.     

Spectral, IR and magnetic studies of Mn(II), Co(II), Ni(II) and Cu(II) complexes with pyrrole-2-carboxyaldehyde thiosemicarbazone (L)

Mn(II), Co(II), Ni(II) and Cu(II) complexes are synthesized with thiosemicarbazone (L) derived from pyrrole-2-carboxyaldehyde. These complexes are characterized by elemental analysis, molar conductance, magnetic susceptibility measurement, mass, IR, electronic and EPR spectral studies. The molar conductance measurement of the complexes in DMSO indicates that the complexes are non-electrolyte except Co(L)2(NO3)2 and Ni(L)2(NO3)2 complexes which are 1:2 electrolyte. All the complexes are of high-spin type. On the basis of spectral studies an octahedral geometry may be assigned for Mn(II), Co(II) and Ni(II) complexes except Co(L)2(NO3)2 and Ni(L)2(NO3)2 which are of tetrahedral geometry. A tetragonal geometry may be suggested for Cu(II) complexes.     

铕（III）牛磺酸席夫碱配合物的合成、表征及其与DNA的作用模式

合成了三种铕(III)与牛磺酸缩水杨醛席夫碱配合物 [(Eu(TSal)L(NO3)) •2H2O,TSal ：席夫碱配体,L1：1,10-邻菲咯啉,L2：2- 氨基吡啶,L3：2,2’-联吡啶],并对其进行了结构表征;采用荧光光谱法和粘度法研究了配合物与小牛胸腺DNA的相互作用模式。实验结果表明三种配合物对DNA均有不同强度的插入作用,其插入能力在一定范围内与配合物的浓度正相关,且与配合物分子适宜的平面性有关,三种配合物对DNA插入能力顺序为：[Eu(TSal)L1(NO3)]•2H2O＞[Eu (TSal)L3(NO3)] •2H2O＞[Eu(TSal) L2(NO3)]• 2H2O。     

Synthesis, characterization and electrochemical studies of mixed ligand complexes of ruthenium(ii) with DNA

Two mixed ligand complexes of ruthenium(ii) [Ru(bzimpy)(bpy)(OH(2))](2+) (1) and [Ru(bzimpy)(phen)(OH(2))](2+) (2) have been synthesized and characterized by FAB mass, (1)H NMR, cyclic voltammetry and spectroelectrochemical measurements. Controlled potential electrolysis of these complexes results in the conversion of ruthenium(ii) to ruthenium(iii) at 0.6 V and ruthenium(iii) to ruthenium(iv) at 0.8 V vs. SCE. The binding constant of these complexes with DNA has been determined electrochemically and found to be (3.58 +/- 0.25) x 10(4) and (2.87+/- 0.2) x 10(4) M(-1). Viscosity measurements suggest that these complexes bind with DNA through intercalation. Such intercalative binding to DNA has been found to induce chirality to the two complexes. Electrochemically generated ruthenium(iv) species of these complexes have been found to bring about oxidative cleavage in DNA.     

Polymer complexes XXXVII novel models and structural of symmetrical poly-Schiff base on heterobinuclear complexes of dioxouranium(VI)

Some binary and ternary novel complexes of dioxouranium(VI) with 5-vinylsalicylaldehyde (VSH) have been prepared and characterized by various physico-chemical techniques. The amine exchange reactions of coordinated poly-Schiff bases in these complexes have been also carried out which give symmetrical tetradentate poly-Schiff base complexes. Metal exchange reaction of these dioxouranium(VI) complexes with copper(II) gives the corresponding Cu(II) complexes. Reaction of tetradentate poly-Schiff base complexes of Cu(II) so obtained with ZrCl4 gives heterobinuclear polymer complexes. Magnetic, electronic and IR spectral information commensurate that configurations of square planar copper(II) polymer complexes. All the polymer complexes are coloured and appear to be nonelectrolytes in DMF. The ligands behave as bi-(O, O) and tetradentate (N2, O2) donors. El-Sonbati equation was used to evaluate the symmetric stretching frequency from which the fU-O and fUO, UO- were calculated.