Electrochemistry of Interaction Between Flavin Mononucleotide (FMN) and PM-17 as Antitumoral ε-Keggin Core Compound, \left[ {{\text{H}}_{ 2} {\text{Mo}}_{ 1 2}^{\text{V}} {\text{O}}_{ 2 8} \left( {\text{OH}} \right)_{ 1 2} \left( {{\text{Mo}}^{\text{VI}} {\text{O}}_{ 3} } \right)_{ 4} } \right]^{ 6- } at pH 7.5

In order to obtain a clue to the antitumor mechanism of $\left[ {{\text{Me}}_{ 3} {\text{NH}}} \right]_{ 6} \left[ {{\text{H}}_{ 2} {\text{Mo}}_{ 1 2}^{\text{V}} {\text{O}}_{ 2 8} \left( {\text{OH}} \right)_{ 1 2} \left( {{\text{Mo}}^{\text{VI}} {\text{O}}_{ 3} } \right)_{ 4} } \right]$ ·2H₂O (PM-17), the interaction of PM-17 with flavin mononucleotide (FMN) as a prosthetic group of the flavoprotein has been investigated by both polarographic analysis and isothermal titration calorimetry (ITC) technique at the physiological solution pH (7.5). The half-wave potential (?0.50 V vs. Ag/AgCl) of the d.c. polarogram for the quasi-reversible one-electron reduction of FMN was shifted by PM-17 toward a more positive potential with a resultant deviation from one-electron reduction to formally more than one-electron reduction waves. The PM-17 effect on the d.c. polarogram could be explained by a variety of FMN···(PM-17)_n (n > 0) aggregates with multiple conformations which was supported by the thermodynamic parameters (ΔH = ?29.7 kJ mol^?1, ΔS = ?28.2 J mol^?1 K^?1, ΔG = ?21.5 kJ mol^?1, and number of FMN in the binding with PM-17 (N) = 0.053 at 20 °C) estimated by the ITC technique. A large conformational change of the FMN domain by the FMN···(PM-17)_n aggregates is suggested to prevent the movement of the FMN centers into close proximity with nicotinamide adenine dinucleotide (NADH) with a resultant depression of the electron transport in NADH dehydrogenase.     

MHD mixed convection of $$ {\text{Al}}_{2} {\text{O}}_{3} $$ Al 2 O 3 –Cu–water hybrid nanofluid in a wavy channel with incorporated fixed cylinder

Journal of Thermal Analysis and Calorimetry - This study deals with mixed convection of $$ {\text{Al}}_{2} {\text{O}}_{3} $$ –Cu–water hybrid nanofluid in a wavy channel having a...     

Direct chemiluminescence determination of fenbufen by the enhancement of the {\text{Ru}}\left( {{\text{phen}}} \right)_3^{2 + } –cerium(IV) system

A method is described for determination of fenbufen that is based on the chemiluminescence (CL) reaction of the ${\text{Ru}}\left( {{\text{phen}}} \right)_3^{2 + } $ –cerium(IV)–fenbufen system. An enhanced CL reaction was developed, and optimum conditions for CL were investigated. The CL was linearly dependent on fenbufen concentration in the range 4.0?×?10^?8–9.0?×?10^?6 mol L^?1. The detection limit was 2.0?×?10^?8 mol L^?1. The relative standard deviation (RSD) was 2.8% for eleven measurements of 6.0?×?10^?7 mol L^?1 fenbufen standard solution. The new method enables simple, sensitive, and rapid determination of fenbufen and has been used for determination of fenbufen in pharmaceutical preparations in capsule, spiked serum and urine samples.     

Mixed-Ligand Complexes Zn(2,2′-Bipy)(ROCS2)2 with Mono- and Bidentate Ligands {\text{ROCS}}_{\text{2}}^ - (R = i-Pr, i-Bu)

The mixed-ligand complexes Zn(2, -Bipy)(i-PrOCS₂)₂ (I) and Zn(2, -Bipy)(i-BuOCS₂)₂ (II) were synthesized. Their structures were solved using the X-ray diffraction data (CAD-4 diffractometer, MoK radiation, 1873 and 1948 F _hkl , R = 0.0357 and 0.0338). The crystals are triclinic with unit cell dimensions a = 10.002(2), b = 11.080(2), c = 11.756(2) , = 78.46(3), = 75.49(3), = 63.50(3)°, V = 1122.9(4) ³, Z = 2, space group (for complex I) and a = 8.760(2), b = 12.520(3), c = 13.252(3) , = 63.93(3), = 71.10(3), = 88.01(3)°, V = 1225.2(5) ³, Z = 2, space group (for II). The structures are based on discrete monomeric molecules. The polyhedra of Zn atoms are tetragonal pyramids (ZnN₂S₃, c.n. 4+1, both bidentate and monodentate ligands coordinated to the Zn atom). The packing of molecules and the character of their interaction in the structures are considered.     

Density functional theoretical study of A series of pentazolide compounds \hbox{A}_{\it n}(\hbox{N}_5)_{\rm 6-{\it n}}^{\it q} (A = B, Al, Si, P, and S; n = 1–3; q = +1, 0, −1, −2, and −3)

The structure and the stability of pentazolide compounds $\hbox{A}_{\it n}(\hbox{N}_5)_{\rm 6-{\it n}}^{\it q}$ (A = B, Al, Si, P, and S; n= 1–3; q = +1, 0, ?1, ?2, and ?3), as high energy-density materials (HEDMs), have been investigated at the B3LYP/6-311+G* level of theory. The natural bond orbital analysis shows that the charge transfer plays an important role when the $\hbox{A}_{\it n}(\hbox{N}_5)_{\rm 6-{\it n}}^{\it q}$ species are decomposed to $\hbox{A}_{\it n}(\hbox{N}_5)_{\rm 5-{\it n}}\hbox{N}_3^{\it q}$ and N₂. The more negative charges are transferred from the N₂ molecule after breaking the N₅ ring, the more stable the systems are with respect to the decomposition. Moreover, the conclusion can be drawn that ${\hbox{Al}(\hbox{N}_5)_5^{2-}}$ and ${\hbox{Al}_2(\hbox{N}_5)_4^{2-}}$ are predicted to be suitable as potential HEDMs.     

SYNTHESIS AND STRUCTURE OF SALTS OF THE N,N′,N″-TRIS(4-(PHENYLDIAZENYL)PHENYL) IMIDOSULFITE ANION – AN ORGANIC ANALOGUE OF $$\mathbf{SO}_{\mathbf{3}}^{\mathbf{2}-}$$

Journal of Structural Chemistry - Reduction of 4,4′-bis-(phenyl azo)-diphenyl thiodiimide S(=N–C6H4–N=N–C6H5)2 (1) in tetrahydrofuran (ТHF) with potassium-intercalated...     

Synthesis and Structure of Ruthenium Complexes $$\rm[{Ph_{3}PR]_2^+[RuCl_6]^{2-}}$$ (R = C2H5, CH=CHCH3, CH2CH=CHCH3, CH2OCH3), and $$\rm[{Ph_{3}PCH_2CH=CHCH_2{PPh_3}]_2^{2+}[Ru_2Cl_{10}O]^{4-}}$$[Ph3PCH2CH=CHCH2PPh3]22+[Ru2Cl10O]4−· 4H2O

Complexes \(\rm[{Ph_{3}PR]_2^+[RuCl_6]^{2-}}\), where R = C₂H₅ (I), CH=CHCH₃ (II), CH₂CH=CHCH₃ (III), and CH₂OCH₃ (IV), have been prepared by the reaction between ruthenium(III) chloride hydrate and triphenylorganylphosphonium chlorides in dimethylsulfoxide in the presence of hydrochloric acid. A hydrochloric acid solution of ruthenium(III) chloride hydrate when mixed with an aqueous solution of 2-butylene-1,4- bis(triphenylphosphonium dichloride) followed by recrystallization from dimethylsulfoxide results in complex \(\rm[{Ph_{3}PCH_2CH=CHCH_2{PPh_3}]_2^{2+}[Ru_2Cl_{10}O]^{4-}}\)· 4H₂O (V). According to X-ray diffraction data, phosphorus atoms in mono- and binuclear cations have slightly distorted tetrahedral coordination (CPC 105.54(13)°?113.00(8)°, P?C 1.758(9)?1.839(7) Å). In slightly distorted octahedral anions [RuCl₆]^2? of complexes I–IV, the Ru?Cl bond lengths vary in the range 2.3222(6)?2.340(2) Å; the cis-ClRuCl and trans-ClRuCl angles are 89.133(18)°–90.867(18)° and 179.53(13)°–180°, respectively. In the binuclear [(RuCl₅)₂O]^4? anion of complex V, RuCl₅ fragments are bonded by a bridging oxygen atom. The Ru–Cl bond lengths fall in the range 2.3375(8)?2.3957(8) Å; the Ru–O bond length is 1.7832(2) Å. The cis-ClRuCl, trans-ClRuCl, cis-ORuCl, and trans-ORuCl angles are 86.67(3)°?91.28(3)°, 174.60(3)°?174.83(3)°, 91.49(2)°?93.65(2)°, and 178.39(2)°, respectively. In crystals I–V, interionic hydrogen bonds Cl···H_cation (2.63?2.95 Å), Cl··· \({\rm{H}_{{H_2}O}}\) (2.35?2.79 Å), and H_cation···\({\rm{O}_{{H_2}O}}\) (1.72?1.93 Å) (for V) are found.     

Di-tert-butylcyclopentadienyl complexes of europium and ytterbium: synthesis and crystal structures of (1,3-But 2C5H3)2 Eu·THF, (1,3-But 2C5H3)(C5Me5)Yb·THF, and\left( {1,3 - Bu^t _2 C_5 H_3 } \right)_2 Yb(\mu _2 - Cl)_2 Li(THF)_2

The (1,3-Bu^t ₂C₅H₃)₂Eu·THF complex was prepared by the reaction of 1,3-Bu^t ₂C₅H₃Na with Eul₂ in tetrahydrofuran. The mixed-ligand (1,3-Bu^t ₂C₅H₃)(C₅Me₅)Yb·THF complex was obtained by the reaction of YbI₂ with C₅Me₅Na and 1,3-Bu^t ₂C₅H₃Na. The reaction of 1,3-Bu^t ₂C₅H₃Li with YbCl₃ afforded the ( $\left( {1,3 - Bu^t _2 C_5 H_3 } \right)_2 Yb(\mu _2 - Cl)_2 Li(THF)_2 $ )ate-complex. The structures of the title compounds were established by X-ray diffraction analysis.     

Synthesis,Structure and Property of a 1D Coordination Polymer [Mn{5-（NO2）sal}2（phen）]n with 5-Nitrosalicylate Ligand

A new coordination polymer [Mn{5-（NO2）sal}2（phen）]n （5-（NO2）sal = 5-nitrosalicylate, phen = 1,10-phenanthroline） was synthesized by a hydrothermal reaction and characterized by elemental analysis, IR and X-ray single-crystal diffraction. The title complex crystallizes in orthorhombic, space group Pbcn with α = 25.747（8）, b = 13.220（4）, c = 7.009（3） A, V= 2386（1）A^3, Z = 4, R = 0.0427 and wR = 0.0890. The 5-nitrosalicylate anions doubly bridge the Mn（Ⅱ） atoms to form a one-dimensional polymeric chain with repeated eight-membered ring units （Mn-O-C-O）2. The crystal structure is stabilized by intra- and interchain hydrogen bonding interactions. The cyclic voltammetric behavior of the title complex is also reported.     

Synthesis,Structure, and Luminescent Property of a 3-D Zinc Complex { [ZN8II（4-APha）8（CH3COO）8] （CH3CH2OH）2}n①

The title complex [ZnⅡ8(4-APha)8(CH3COO)8(CH3CH2OH)2]n(1, 4-APha = 4-aminophenylhydroxamic acid) has been prepared under solvothermal conditions. It has been characterized by X-ray single-crystal diffraction, IR and elemental analysis. The crystal belongs to the monoclinic system, space group C2/c with a = 39.074(4), b = 9.9645(8), c = 38.846(3) A, β = 136.438 o, V = 10423.1(14) A3, C84H118N16O39Zn8, Mr = 2498.90, Z = 4, Dc = 1.592 g/cm3, μ = 1.900 mm-1, F(000) = 5144, the final R = 0.1036 and wR = 0.2953. This complex possesses a 3-D structure which is constructed from 1-D chain motifs linked by the 4-APha- ligands. The luminescent property of the title complex has been investigated.     

Pseudo-Polymeric Mercury(II) Morpholinedithiocarbamate [Hg{S2CN(CH2)4O}2]n: Supramolecular Structure (a Role of Secondary Hg···S Bonds), 13C and 15N CP-MAS NMR Spectra,and Thermal Behavior

Russian Journal of Coordination Chemistry - A new representative of mercury(II) dithiocarbamate complexes, crystalline bis(morpholinedithiocarbamato-S,S')mercury(II) with the...