bluuebunny/crossref_metadata_2025_split huggingface dataset:
1,3‐Dipolar Cycloaddition of Nitrones with Electron‐rich Alkenes Catalyzed by Yb(OTf)3
Authors: Qian Chang‐Tao , Wang Long‐Cheng , Chen Rui‐Fang 
Published: September 2010

Abstract1,3‐Dipolar cycloaddition of nitrones with ethyl vinyl ether or 2,3‐dihydrofuran proceeds smoothly in the presence of a catalytic amount (10 mol%) of ytterbium triflate to afford isoxazolidines and dicyclic isoxazolidine respectively with good yields and high stereoselectivity.
Electrostatic Layer‐by‐Layer Assembly of Polycation and DNA Multilayer Films by Real‐time Surface Plasmon Resonance Technique
Authors: Pei Ren‐Jun , Cui Xiao‐Qiang , Yang Xiu‐Rong , Wang Er‐Kang 
Published: September 2010

AbstractThe assembly of alternating DNA and positively charged poly‐(dimethyldiallylammonium chloride) (PDDA) multilayer films by electrostatic layer‐by‐layer adsorption has been studied. Real time surface plasmon resonance (BIAcore) technique was used to characterize and monitor the formation of multilayer films in solution in real time continuously. The results indicate that the uniform multilayer can be obtained on the poly‐(ethylenimine) (PEI) coated substrate surface. The kinetics of the adsorption of DNA on PDDA surface was also studied by real‐time BIAcore technique, and the observed rate constant was calculated using a Langmuir model (kobs = (1.28 ± 0.08) × 10−2s−1).
Studies on Self‐diffusion of Main Components of Hop Oils
Authors: Chen Liu‐Ping , Groβ Thomas , Lüdemann Hans‐Dietrich 
Published: September 2010

AbstractThe self‐diffusion coefficients (D) of α‐humulene and myrcene, which are main components of hop oils, were measured at the temperature range of 274‐372 K and pressures up to 100 MPa by the Stejskal‐Tanner FT NMR method. In order to obtain motional behavior of the molecules in the supercritical conditions, the intradiffusion coefficients (Dü) of the two substances in carbon dioxide were also determined. It was found that the values of Dü are about one order of magnitude higher than that for the pure components at the same‐ranges of temperature and pressure. The self‐diffusion data of α‐humulene and myrcene are analysed, and the diffusion behavior of these compounds is discussed.
Synthesis and Structure of Novel Double Flexible Spacer Bridged Biscalix[4]arenes
Authors: Zeng Xian‐Shun , Weng Lin‐Hong , Chen Lang‐Xing , Ju Hong‐Fang , Leng Xue‐Bing , He Xi‐Wen , Zhang Zheng‐Zhi 
Published: September 2010

Abstract25, 25′, 27, 27′‐Bis(1,3‐dioxypropane)‐bis(5, 11, 17, 23‐tetra‐tert‐butylcalix[4]arene‐26,28‐diol) (4) and 25, 25′, 27, 27′‐bis(1, 4‐dioxybutane)‐bis (5, 11, 17, 23‐tetra‐tert‐butylcalix‐[4]arene‐26, 28‐diol) (5) were synthesized by the reaction of p‐tert‐butylcalix[4]arene (1) with preorganized 25, 27‐bis(3‐bromoproxyl)calix[4]arene‐26, 27‐diol (2) and 25, 27‐bis(3‐bromobutoxyl)calix[4]arene‐26, 27‐diol (3) in the presence of K2CO3 and KI. Compounds 4 and 5 were characterized with X‐ray analysis and the selectivity of 4 and 5 toward K+ over other alkali metal ions, alkaline metal ions as well as NH4+ were investigated with an ion‐selective electrode.
Calculation of Mass and Abundance for Polyisotopic Ion by Low Resolution Mass Spectrometry
Authors: Yu Chong‐Tian , Guo Yin‐Long , Zhang Zun‐Jian , Xiang Bing‐Ren , An Deng‐Kui 
Published: September 2010

AbstractThe new algorithm calculated mass and abundance for polyisotopic ion by low‐resolution mass spectrometry was developed based on probability theory. The results of mass and abundance data of polyisotopic ion calculated by the algorithm were coincided with the experimental values. By comparison with the Kubinyi's method, our algorithm is simpler and easier to master for operator.
Sardisterol, A New Polyhydroxylated Sterol from the Soft Coral Sarcophyton digitatum Moser
Authors: Su Jing‐Yu , Yang Ruo‐Lin , Zeng Long‐Mei 
Published: September 2010

AbstractA new polyhydroxylated sterol, named sardisterol, was isolated from the soft coral Sarcophyton digitatum Moser. Its structure was determined as (22R, 24ξ)‐methylcholest‐5‐en‐3β, 22, 25, 28‐tetraol‐3‐acetate on the basis of spectroscopic methods.
A New Synthetic Approach to Coumestan Derivatives
Authors: Gong Deng‐Huang , Li Chao‐Zhong , Yuan Cheng‐Ye 
Published: September 2010

AbstractA new method for the preparation of coumestan derivatives was described involving an intramolecular palladium‐catalyzed ring closure reaction of coumarins obtained from condensation of substituted o‐hydroxyphenylacetic add and o‐hydroxybenzaldehyde.
A Convenient Synthesis and Molecular Structure of Ru(CO)3[Ph2PN(i‐Bu)PPh2‐P, P]
Authors: Xu Feng‐Bo , Zhang Zheng‐Zhi 
Published: September 2010

AbstractRu(CO)3 [Ph2PN (i‐Bu) PPh2‐P, P] was conveniently obtained by the reaction of Ru(DMSO)4Cl2 with Ph2PN(i‐Bu)‐PPb2 and CO in the presence of Zn powder under mild conditions. The crystal and molecular structure was determined by X‐ray diffraction. This compound possesses a distorted trigonal bipyramidal configuration.
Synthesis of Allyl Selenides Promoted by an Sm/ZnCl2 Bimetal System in the Presence of Water
Authors: Zheng Yuri‐Fa , Guo Hong‐Yun , Zhang Yong‐Min 
Published: September 2010

AbstractThe reaction of diselenides with allylic bromides proceeded smoothly in an Sm/ZnCl2 bimetal system in THF‐H2O to afford allyl selenides in good yield.
Engineering Chiral Catalysts through Asymmetric Activation and Super High Throughput Screening (SHTS)
Authors: Mkami Koichi , Korenaga Toshinobu , Matsukawa Satoru , Ding Kui‐Ling , Long Jiang 
Published: September 2010

AbstractA conceptually new strategy for asymmetric catalysis, namely asymmetric activation, in which a chiral activator selectively activates one enantiomer of a racemic chiral catalyst, and a highly efficient screening system for finding the most effective catalysts, namely super high throughput screening (SHTS), by which the reaction can be conducted in parallel and the ee% of the product is allowed to determine within minutes, are summarized in the present account. It is reasonable to believe that SHTS technique combined with asymmetric activation or deactivation principle will provide a very powerful methodology for finding the new catalysts and the best catalyst tuning for asymmetric reactions.
Theoretical Investigation on the Reactions of H with (CH3)4‐nSiHn (n = 1–4)
Authors: Zhang Qing‐Zhu , Zhang Ji‐Guo , Wang Shao‐Kun , Zhang Miao , Liu Chuan‐Pu , Gu Yue‐Shu 
Published: September 2010

AbstractThe abstractions of H with (CH3)4‐nSiHn (n = 1–4) have been investigated at high levels of ab initio molecule orbital theory. Geometries have been optimized at the MP‐2 level with 6–31G(d) basis set, and G2MP2 level has been used for the final energy calculations. Theoretical analysis provided conclusive evidence that the main process occurring in each case is the abstraction of H from the SiH bond leading to the formation of the H2 and silyl radicals; the abstraction of H from CH bond has higher barrier and is difficult to react in each case. The kinetics of the title reactions have been calculated with variational transition state theory over the temperature range 200–1000 K, and the theoretical rate constants match well with the experimental values.
A New Method to Measure Electroosmotic Flow Mobility of Capillary Electrophoresis by Abrupt Change of Current De‐noising via Wavelet Transform
Authors: Li Qian‐Feng , Zhang Xiao‐Yun , Zhang Hong‐Yi , Chen Xing‐Guo , Liu Man‐Cang , Hu Zhi‐De 
Published: September 2010

AbstractThe electroosmotic flow mobility has been measured by the combination of monitoring the change in electric current during electrophoretic run and operating the wavelet transform. Once the sample solvent zone with different ionic strength from background electrolyte migrated from the capillary, a sudden change in current could be observed from the electric current record of time history. The exact time (in the middle of abrupt range) corresponding to the abrupt change in current was determined by wavelet transform. This work showed that the electroosmotic flow mobility determined by the proposed method was in a good agreement with the neutral marker method commonly used.
Novel Lanthanide Complexes of Ciprofloxacin: Synthesis, Characterization, Crystal Structure and in vitro Antibacterial Activity Studies
Authors: Li Jia‐Bin , Yang Pin , Gao Fei , Han Gao‐Yi , Yu Kai‐Bei 
Published: September 2010

AbstractNovel lanthanide coordination compounds with ciprofloxacin (CPFX), including eleven complexes Ln(CPFX)2Cl(H2O), (Ln=Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb; n = 7, 8, 9) and crystalline [Ce(CPFX)2 (H2O)4] Cl (H2O)3.25 (C2H5‐OH)0.25, were synthesized. The crystal is of triclinic space group Pi with a= 1.3865(2) nm, b = 1.3899(3) nm, c = 1.6505(2) nm, a = 92.73(1)°, β= 114.39(1)°, γ=115.55 (1)°, Z = 2 and R = 0.0449. FT‐IR, electronic spectroscopy and X‐ray diffraction were employed to show that the lanthanide ion, which displays an eight‐coordinate structure, is chelated by 3‐carboxyl and 4‐keto oxygen donors of CPFX and two six‐membered chelate rings are formed. Test of in vitro antibacterial activity against E. coli, P. aeruginosa and S. aureus indicated that the in vitro antibacterial activity of the ligand can be improved by complexation with Ce(III).
Triterpenoid Saponins from Vaccaria segetalis
Authors: Ma Ji , He Fa‐Hu , Deng Jing‐Zhen , Ye Wen‐Cai , Zhao Shou‐Xun , Wu Hou‐Ming 
Published: September 2010

AbstractFour novel triterpenoid saponins, Vaccariside B‐E (1–4), were isolated from the seeds of Vaccaria segetalis and their structures were elucidated as 3‐O‐β‐D‐galactopyranosyl‐(1–2)‐β‐D‐glucuronopyranosyl quillaic add 28‐O‐β‐D‐xylopyranosyl‐(1–3)‐α‐L rhamno‐pyranosyl‐(1–2)‐[α‐L‐arabinofura‐nosyl‐(1–3)]‐4‐O‐acetyl‐β‐D)‐fucopyranoside (1), 3‐O‐β‐D‐galactopyranosyl ‐ (1–2) −3‐O‐acetyl‐β‐D ‐ glucuronopyranosyl quillaic acid 28‐O‐β‐D‐xylopyranosyl‐(1–3)‐α‐L‐rhamnopyra‐nosyl‐(1–2)‐[α‐L‐arabinofuranosyl‐(1–3)]‐4‐O‐acetyl‐β‐D‐fucopyranoside (2), 3‐O‐β‐D‐galactopyranosyl‐(1–2)‐β‐D‐glucuronopyranosyl quillaic add 28‐O‐α‐L‐arabinopyranosyl‐(1–3)‐α‐L‐rhamnopyranosyl‐(1–2)‐[α‐L‐arabinofuranosyl‐(1–3)]‐4‐O‐acetyl‐β‐D‐fucopyranoside (3), 3‐O‐β‐D‐galacto‐pyranosyl‐(1–2)‐[β‐D‐xytopyranosyl‐(1–3)]‐β‐D‐glucurono‐pyranosyl quillaic add 28‐O‐β‐D‐xylopyranosyl‐(1–3)‐α‐L‐rhamnopyranosyl‐(1–2)‐[α‐L‐arabinofuranosyl‐(1–3)]‐4‐O‐acetyl‐β‐D‐fucopyranoside (4), respectively.
Electrochemical Polymerization of Methylene Green
Authors: Zhu Hong‐Ping , Mu Shao‐Lin 
Published: September 2010

AbstractThe electrochemical polymerization of methylene green has been carried out using cyclic voltammetry. The electrolytic solution consisted of 4° 10−3 mol/L methylene green, 0.1 mol/L NaNO3 and 1 × 10−2 mol/L sodium tetraborate with pH 11.0. The temperature for polymerization is controlled at 60°C. The scan potential is set between −0.2 and 1.2 V (vs. Ag/AgCl with saturated KCl solution). There are an anodic peak and a cathodic peak on the cyclic voltammogram of poly (methylene green) at pH≤3.8. Both peak potentials shift towards negative potentials with increasing pH value, and their peak currents decrease with increasing pH value. Poly (methylene green) has a good electrochemical activity and stability in aqueous solutions with pH≤3.8. The UV‐Visible spectrum and FTIR spectrum of poly (methylene green) are different from those of methylene green.
Chiral Camphor Derivatives as New Catalysts for Asymmetric Phase‐Transfer Alkylation
Authors: Zhang Jie , Wu Xin‐Yan , Zhou Qi‐Lin , Sun Jie 
Published: September 2010

AbstractThe synthesis of new chiral phase‐transfer catalysts based on the optical camphor is described. The alkylation of the benzophenone imine of glycine tert‐butyl ester with benzyl bromide in the presence of new chiral phase‐transfer catalysts afforded the desired alkylation product in good yields and up to 39% ee.
Novel Bonding Character of the Cyclic AlS2 and GaS2 Systems
Authors: Song Xin‐Yu , Nie Yi , Bu Yu‐Xiang 
Published: September 2010

AbstractThe geometries, the harmonic vibrational frequencies and the bonding properties have been predicted for cyclic AlS2 and GaS2 species at the density functional theory (DFT), MPn (n = 2, 3, 4), QCISD(T) and CCSD(T) levels with 6‐311 + G (2df) basis set. The novel bonding character was discussed.
Effect of Substituents on Aggregation Behaviors of Stilbazole and Stilbazolium Derivatives
Authors: Yang Wen‐Sheng , Jiang Yue‐Shun , Wang De‐Jun , Li Tie‐Jin 
Published: September 2010

AbstractStilbazole and stilbazolium derivatives with dialkylaniline as electron pushing substituents and pyridine or pyridinium substituents as electron drawing substituents were synthesized and their aggregation behaviors were studied by UV‐visible, fluorescence and surface photovoltage spectroscopies. Experimental results indicate that the formation of aggregates can be mediated by the electron drawing ability of the substituents introduced for those compounds all bearing strong electron pushing substituent. When the electron drawing substituent is pyridine group, the molecules tend to aggregate in head‐to‐tail manner, whereas the substituent is pyridinium group, the molecules tend to aggregate in face‐to‐face manner. The effect of electron pushing and drawing ability of the substituents on the aggregation behavior is further analyzed in terms of frontier orbital interactions.
Interactions of Safranin T with Nucleic Acids
Authors: Wang Zhen‐Xin , Liu Dian‐Jun , Dong Shao‐Jun 
Published: September 2010

AbstractThe interactions of Safranin T (ST) with several nucleic acids have been investigated by electrochemical, UV‐visible and CD spectroscopic techniques. The form of the nucleic acid‐ST complexes is sensitive to the ratio of the two species. Two electrochemically inactive complexes such as, nucleic acid‐ST and nucleic acid‐2ST, were formed while ST interacts with nucleic acids. Two processes were obtained from spectral experiments: (1) at the high value of R (R is defined as the ratio of the total concentration of ST to that of nucleic acid), ST is groove‐binding with stacking, (2) at the low value of R, ST is groove‐binding without stacking. Intrinsic binding constants were obtained by spectral methods. The experiments also show that electrostatic binding plays an important role in the interaction of ST with nucleic acids.
Determination of Dissociation Constants of Complicated Compounds by Capillary Zone Electrophoresis
Authors: Liu Hai‐Xing , Yang Geng‐Liang , Wang De‐Xian , Sun Su‐Fang , Ma Jian‐Jun 
Published: September 2010

AbstractIn this work, the whole theoretical methods for the determination of pKa1. and pKa2. of complicated compounds are proposed by capillary zone electrophoresis. The pKa values are achieved by non‐linear regression analysis by taking into consideration the effect of activity coefficient. This is the first report on determining the dissociation constants of gastrodin, magnolol, honokiol, quercetin, curcumin, diethylstilbestrol, 4‐acetamidophenol, eugenol and paeonol.
Structure and Photochemical Properties of r‐1, c‐2, t‐3, t‐4‐l, 3‐Bis [2‐ (5‐R‐benzoxazolyl) ] −2,4‐di (4‐R' ‐phenyl) cyclobutane
Authors: Zhang Wen‐Qin , Zhuang Jun‐Peng , Li Chun‐Bao , Sun Hao , Yuan Xue‐Ning 
Published: September 2010

Abstractr‐1, c‐2, t‐3, t‐4‐1,3‐Bis[2‐(5‐R‐benzoxazolyl)]‐2,4‐di(4‐R'‐phenyl)cyclobutane (IIa: R=R' = H; IIb: R=Me, R'= H; IIc: R = Me, R' = OMe) was synthesized with high stereo‐selectivity by the photodimerization of trans‐l‐[2‐(5‐R‐benzoxazolyl)]‐2‐(4‐R'‐phenyl) ethene (Ia: R=R' = H; Ib: R = Me, R' = H; Ic: R = Me, R' = OMe) in sulfuric acid. The structures of IIa–IIc were identified by elemental analysis, IR, UV, 1H NMR, 13C NMR and MS. The molecular and crystal structure of IIc has been determined by X‐ray diffraction method. The crystal of IIc (C34H30N2O4. 0.5C2OH) is monoclinic, space group P21/n with cell dimensions of a = 1.5416(3), b =0.5625(1), c = 1.7875(4) nm, β = 91.56 (3)°, V= 1.550(1) nm3, Z = 2. The structure shows that the molecule of IIc is centrosymmetric, which indicates that the dimerization process is a head‐to‐tail fashion. The selectivity of the photodimerization of Ia–Ic has been enhanced by using acidic solvent and the reaction speed would be decreased when electron donating group was introduced in the 4‐position of the phenyl group. That the photodimerization is not affected by the presence of oxygen as well as its high stereo‐selectivity demonstrated that the reaction proceeded through an excited singlet state. It was also found that under irradiation of short wavelength UV, these dimers underwent photolysis completely to reproduce its trans‐monomers, and then the new formed species changed into their cis‐isomers through trans‐cis isomerization.
Slowing Down in Chemical Tristability Systems
Authors: Zhan Ye‐Hong , Zhang Chun‐Hua , Wu Fu‐Gen , Hu Yi‐Hua 
Published: September 2010

AbstractIn this paper two kinds of slowing down in the chemical tristability systems are studied. One is the critical slowing down at the edges of tristable region, and the other is the slowing down far from the critical point, which has much to do with the unstable steady‐points. The results possess some universal properties.
Theoretical Study of the Unimolecular Decomposition Mechanism of Chloromethanol
Authors: Wang Shao‐Kun , Zhang Qing‐Zhu , Hou Hua , Wang Bin , Liu Fu‐Xiang , Gu Yue‐Shu 
Published: September 2010

AbstractThe decomposition pathways of chloromethanol have been studied by ab initio calculation. Equilibriums and transition states have been optimized at the UMP2(full)/6–31G(d) level. The single point energies have been obtained at higher level of G3 (MP2). Four transition states and eight reaction pathways have been revealed and the most favorable reaction to decomposition pathway is the 1, 2‐HCI elimination, which is consistent with the former scientist's conclusion.
Hydrophobically Modified Polyelectrolytes: V. Interaction of Fluorocarbon Modified Poly (acrylic acid) with Various Added Surfactants
Authors: Zhou Hui , Song Guo‐Qiang , Guo Jin‐Feng , Zhang Yun‐Xiang , Dieing Reinhold , Ma Lian , Haeussling Lukas 
Published: September 2010

AbstractThe interactions between fluorocarbon‐modified poly (sodium acrylate) and various kinds of added surfactants have been studied by means of viscometric measurement. Association behavior was found in both hydrogenated and fluorinated anionic, nonionic and cationic surfactants. Among them, the interactions between fluorocarbon‐modified poly (sodium acrylate) and cationic surfactants are the strongest, owing to the cooperation of both electrostatic attractions and hydrophobic associations. The anionic surfactants have the weakest effects on the solution properties because of the existence of unfavorable electrostatic repulsion. The hydrophobic interactions between copolymers and fluorinated surfactants are much stronger than those between copolymers and hydrogenated surfactants.
MEDV‐13 for QSAR Studies on the COX‐2 Inhibition by Indomethacin Amides and Esters
Authors: Liu Shu‐Shen , Yin Chun‐Sheng , Shi Yun‐Yu , Cai Shao‐Xi , Li Zhi‐Liang 
Published: September 2010

AbstractA molecular electronegativity distance vector based on 13 atomic types (MEDV‐13), is a descriptor for predicting the biological activities of molecules based on the quantitative structure‐activity relationship (QSAR). The MEDV‐13 with 91 descriptors is employed to describe the structures of a series of selective cyclooxygenase‐2 (COX‐2) inhibitors including 16 indomethacin and its amide and ester derivatives (ImAE). A principal component regression (PCR) is used to derive a QSAR model relating the biological activities expressed by p/C50 values to the MEDV‐13. With the number of principal components of 6, the correlation coefficient (R) and the root mean square error (RMS) are 0.9245 and 0.1682 in modeling stage, and 0.8417 and 0.2389 in leave‐one‐out prediction step, respectively.
Electrospray Mass Spectrometry Study on Polynuclear Pd(II) and Ni (II) Complexes of 3, 6, 9, 16, 19, 22‐Hexaazatricyclo [22. 2.2.211,14] triaconta‐11, 13, 24, 26 (1), 27, 29‐Hexaene
Authors: He Wei‐Jiang , Liu Fang , Ye Zhi‐Feng , Mei Yu‐Hua , Guo Zi‐Jian , Zhu Long‐Gen 
Published: September 2010

AbstractPolynuclear Pd(II) and Ni(II) complexes of macrocyclic polyamine 3,6,9,16,19,22‐hexaazatricyclo[22.2.2.211,14]‐triaconta 11,13,24,26(l),27,29‐hexaene (L) in solution were investigated by electrospray ionization mass spectrometry (ESIMS). For methanol solution of complexes M2LX4 (M = Pd(II) and Ni(II), X= Cl and I), two main clusters of peaks were observed which can be assigned to [M2LX3]+ and [M2LX2]2+. When Pd2LCl4 was treated with 2 or 4 mol of AgNO3, it gave rise formation of Pd2LCl2 (NO3)2 · H2O and [Pd2L(H2O)m(NO3)n](4‐n)+, respectively. ESMS spectra show that the dissociation of the former in the ionization process gave peaks of [Pd2LCl2]2+ and [(Pd2LCl2)NO3]+, while dissociation of the later gave the peaks of [Pd2L(CH3CO2)2]2+ and [Pd2L(CH3CO2)2](NO3) + in the presence of acetic acid. Similar species were observed for Pd2LI4 when treated with 4 mol of AgNO3. When [Pd2L · (H2O)m(NO3)n](4‐n)+ reacted with 2 mol of oxalate anions at 40°C, [Pd4L2(C2O4)2(NO3)2]2+ and [Pd4L2(C2O4)2 (NO3)]3+ were detected. This implies the formation of square‐planar molecular box Pd4L2(C2O4)2(NO3)4 in which C2O4− may act as bridging ligands as confirmed by crystal structure analysis. The dissociation form and the stability of complex cations in gaseous state are also discussed. This work provides an excellent example of the usefulness of ESIMS in the identification of metal complexes in solution.
Crystal Structure and Luminescence of [Eu(TTA)3·DAF]·0.5C7H8 Complex Excited by Visible Light
Authors: Liu Hul‐Biao , Li Bao‐Long , Wang Hua‐Qin , Xu Zheng 
Published: September 2010

AbstractThe non‐ionic europium(III) complex [Eu(TTA)3·DAF]·0.5C7H8 (TTA = 2‐thenoytrifluoroacetonate, DAF = 4, 5‐diazafluoren‐9‐one) was synthesized. The structural determination has been carried out. DAF coordination induces the both excitation spectra in the solid state and solution having a red shift and sensitizes Eu3+ luminescence under visible light excitation.
A New Dinuclear Copper (II) Complex of a Bis‐macrocyclic Ligand: Synthesis, Characterization, Crystal Structure and Magnetic Properties
Authors: Du Miao , Xu Qiang , Guo Ya‐Mei , Weng Lin‐Hong , Bu Xian‐He 
Published: September 2010

AbstractA new dinuclear Cu(II) complex, [Cu2L(N3)2](ClO4)1.5 (OH)4.5 · 2H2O 0.5C2H5OH (1), of a bis‐macrocyclic ligand, 2,6‐bis(l,4,7,10‐tetraazacyclododecan‐10‐ylmethyl)‐methoxybenzene (L), has been synthesized, characterized and structurally determined by X‐ray diffraction analysis. Complex 1 crystallizes in orthorhombic crystal system, Pca2(l) space group with a = 1.5371(3), b = 1.6641(3), c = 3.0950(6) nm, V = 7.917(3) nm3, Fw = 904.62, Z=8, Dc= 1.529 g/cm3 and final R = 0.0568, wR = 0.1406 for 10410 observed reflections with I≥2σ (I). Both Cu(II) centers in the structure are coordinated by four nitrogen atoms of 1,4,7, 10‐tetraazacyclododecane (cyclen) and a nitrogen donor of the axial azide anion. Each Cu(II) center is in a square‐pyramidal coordination environment, and the intra‐and nearest inter‐molecular CuCu nonbonding distances are 0.9855 and 0.7298 nm, respectively. Variable temperature magnetic susceptibility measurements in the range of 4.2–300 K indicate mat there exists weak intra‐ and inter‐molecular antiferromagnetic coupling between the Cu(II) centers with 27= −4.2 cm−1 and Θ = −0.47 K.