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1.
Nina I. Giricheva Georgiy V. Girichev Yulia S. Medvedeva Sergey N. Ivanov Anna V. Bardina Vyacheslav M. Petrov 《Structural chemistry》2011,22(2):373-383
A combined gas-phase electron diffraction and quantum chemical (B3LYP/6-311+G**, B3LYP/cc-pvtz, MP2/cc-pvtz) study of molecular
structure of 2-nitrobenzenesulfonamide (2-NBSA) was carried out. Quantum chemical calculations showed that 2-NBSA has four
conformers, two of which are stabilized by intramolecular hydrogen bond. The latter (with the S–N bond in a close to orthogonal
position around the phenyl ring and differing from each other by staggered or eclipsed positions of the N–H and S=O bonds
in the SO2NH2 group) presented in a saturated vapor over 2-NBSA at T = 433 (3) K in commensurable amounts. Experimental internuclear distances (Ǻ) for the staggered conformer are (?): r
h1(C–H)av. = 1.071(9), r
h1(C–C)av. = 1.390(4), r
h1(C–S) = 1.789(8), r
h1(S=O)av. = 1.427(6), r
h1(S–N) = 1.644(6), r
h1(N–O)av. = 1.221(4), r
h1(C′–N) = 1.487(8), r
h1(N–H)av. = 1.014. Calculations at B3LYP/cc-pvtz level were performed to determine the structure and the energies of the transition
states between conformers. It was shown that the conformer structures of free molecule differ from those of a molecule stabilized
by intermolecular hydrogen bonds in a crystal. Influence of a substituent X (X = –CH3, –NO2) on conformational features of the ortho-substituted benzenesulfonamide was established. 相似文献
2.
The conformational composition of gaseous MTMNB and the molecular structures of the rotational forms have been studied by
electron diffraction at 130∘C aided by results from ab initio and density functional theory calculations. The conformational potential energy surface
has been investigated by using the B3LYP/6-31G(d,p) method. As a result, six minimum-energy conformers have been identified.
Geometries of all conformers were optimized using MP2/6-31G(d,p), B3LYP/6-31G(d,p), and B3LYP/cc-pVTZ methods. These calculations
resulted in accurate geometries, relative energies, and harmonic vibrational frequencies for all conformers. The B3LYP/cc-pVTZ
energies were then used to calculate the Boltzmann distribution of conformers. The best fit of the electron diffraction data
to calculated values was obtained for the six conformer model, in agreement with the theoretical predictions. Average parameter
values (ra in angstroms, angle α in degrees, and estimated total errors given in parentheses) weighted for the mixture of six conformers
are r(C–C) = 1.507(5), r(C–C)ring, av = 1.397(3), r(C–S)av = 1.814(4), r(C–N) = 1.495(4), r(N–O)av = 1.223(3), ∠(C–C–C)ring = 116.0–122.5, ∠ C6–C4–C7 = 118.2(4), ∠ C–C–S = 113.6(6), ∠ C–S–C = 98.5(12), ∠ N–C–C4 = 121.9(3), ∠(O–N–C)av = 116.8(3), ∠ O–N–O = 127.0(4). Torsional angles could not be refined. Theoretical B3LYP/cc-pVTZ torsional angles for the
rotation about C–N bond, φC−N, were found to be 30.5–36.5∘ for different conformers. As to internal rotation about C–C and C–S bonds, values of φC−C = 68–118∘ and φC−S = 66–71∘ were obtained for the three most stable conformers with gauche orientation with respect to these bonds.
Some conclusions of this work were presented in a short communication in Russ. J. Phys. Chem. 2005, 79, 1701. 相似文献
3.
Anna Rita Campanelli Aldo Domenicano Fabio Ramondo István Hargittai 《Structural chemistry》2011,22(2):361-369
The molecular structure of triphenylsilane has been investigated by gas-phase electron diffraction and theoretical calculations.
The electron diffraction intensities from a previous study (Rozsondai B, Hargittai I, J Organomet Chem 334:269, 1987) have
been reanalyzed using geometrical constraints and initial values of vibrational amplitudes from calculations. The free molecule
has a chiral, propeller-like equilibrium conformation of C
3 symmetry, with a twist angle of the phenyl groups τ = 39° ± 3°; the two enantiomeric conformers easily interconvert via three
possible pathways. The low-frequency vibrational modes indicate that the three phenyl groups undergo large-amplitude torsional
and out-of-plane bending vibrations about their respective Si–C bonds. Least-squares refinement of a model accounting for
the bending vibrations gives the following bond distances and angles with estimated total errors: r
g(Si–C) = 1.874 ± 0.004 ?, 〈r
g(C–C)〉 = 1.402 ± 0.003 ?, 〈r
g(C–H)〉 = 1.102 ± 0.003 ?, and ∠aC–Si–H = 108.6° ± 0.4°. Electron diffraction studies and MO calculations show that the lengths of the Si–C bonds in H4−n
SiPh
n
molecules (n = 1–4) increase gradually with n, due to π → σ*(Si–C) delocalization. They also show that the mean lengths of the ring C–C bonds are about 0.003 ? larger
than in unsubstituted benzene, due to a one hundredth angstrom lengthening of the Cipso–Cortho bonds caused by silicon substitution. A small increase of r(Si–H) and decrease of the ipso angle with increasing number of phenyl groups is also revealed by the calculations. 相似文献
4.
Zuzana Vasková Zdenka Padělková Milan Mazur Dušan Valigura Jan Moncol 《Transition Metal Chemistry》2011,36(8):883-889
The synthesis, spectral characterization and crystal structures of two nitrobenzoatocopper(II) complexes, namely [Cu(2-O2Nbz)2(pca)2(H2O)2] (1) and [Cu(3,5-(O2N)2bz)2(pca)2(H2O)2] (2) (where 2-O2Nbz = 2-nitrobenzoate, 3,5-(O2N)2bz = 3,5-dinitrobenzoate, pca = pyrazinecarboxamide), are reported. Complexes 1 and 2 consist of centrosymmetric molecules with the Cu(II) atom monodentately coordinated by a pair of anionic 2-nitrobenzoato
(1) or 3,5-dinitrobenzoato (2) ligands and a pair of pyrazinecarboxamide ligands, forming a nearly tetragonal basal plane, and by a pair of water ligands
that complete the tetragonal–bipyramidal coordination polyhedron. The molecules of both complexes are linked by N–H⋯O and
O–H⋯O hydrogen bonds and lie in planes, which have different orientations depending on the space group. Similar experiments
with 3-nitrobenzoic acid resulted in the isolation of the hydrolysis product [Cu(pyzCOO)2]
n
(3) (pyzCOO = pyrazinecarboxylate). The known crystal structure of complex 3 has been re-determined at low temperature with significantly higher precision. The crystal packing and C–H⋯O/C–H⋯N hydrogen
bonds are discussed. 相似文献
5.
A. López-Hernández K. Venkatesan H. W. Schmalle Heinz Berke 《Monatshefte für Chemie / Chemical Monthly》2009,36(10):845-857
Abstract
Stable paramagnetic Cr(II) and Cr(III) bis(alkynyl) complexes of the type [trans(RC≡C)2Cr(dmpe)2] n+ (R = Ph, SiMe3, SiEt3, C≡C–SiMe3 n = 0, 1) were prepared and characterised by NMR, cyclic voltammetry, EPR, magnetic measurements, and X-ray single-crystal diffraction studies. 相似文献6.
Cyril Rajnák Ján Titi? Roman Bo?a Ján Moncol’ Zdeňka Padělková 《Monatshefte für Chemie / Chemical Monthly》2011,36(4):789-795
Abstract
A mononuclear complex [CoL2Cl2]·3.5H2O (L = 2-[(2,2-diphenylethylimino)methyl]pyridine-1-oxide) has been synthesized and characterized by X-ray structure analysis. The crystal structure confirms the formation of an interesting porous framework with channel diameters of about 8 ? through weak C–H···π and C–H···Cl interactions. The magnetic properties of this complex have also been studied, and the susceptibility and magnetization data were analyzed in terms of the spin Hamiltonian formalism. They confirm substantial zero-field splitting, D/hc = 75 cm−1. 相似文献7.
Synthesis, crystal structures and DNA-binding properties of two new mononuclear copper(II) complexes
Two mononuclear copper(II) complexes, [Cu(bpy)2(CH3OH)](pic)2 (1) and [Cu(Me2bpy)2(H2O)](pic)2 (2) (bpy = 2,2′-bipyridine; Me2bpy = 4,4′-dimethyl-2,2′-bipyridine; Hpic = 2,4,6-trinitrophenol), were synthesized and characterized by elemental analyses,
conductivity measurements, IR, UV–Visible spectroscopy and single crystal X-ray analyses. Both complexes 1 and 2 are mononuclear compounds. The copper atom in complex 1 is in a distorted square pyramidal geometry with a CuN4O chromophore as revealed from the τ value (0.25), while the Cu(II) ion in complex 2 displays a distorted trigonal bipyramidal stereochemistry with τ = 0.72. Hydrogen bonding interactions and π–π stacking interactions
link the mononuclear copper complex 1 or 2 into a 1D infinite chain. The interactions of the two mononuclear complexes with herring sperm DNA (HS-DNA) have been studied by UV–visible absorption titration, fluorescence titration and ethidium bromide (EB) displacement
experiments. The results suggest that both complexes might bind to DNA by intercalation. 相似文献
8.
Limin Han Guangbin Zhang Ning Zhu Ruijun Xie Quanling Suo Meihua Luo Linhong Weng 《Journal of Cluster Science》2010,21(4):789-801
Two novel bimetallic complexes, [Cr(CO)3(η
6-C6H5)–C≡C–C6H4–Fc] (Fc = C5H5FeC5H4] (1) and [Cr(CO)3(η
6-C6H5)–C ≡ C–Fc–C(CH3)2–Fc] (3), were synthesized by the Sonogashira coupling reaction. By using of (1) and (3) as ligands to react with Co2(CO)8, two others novel polymetallic complexes, [Cr(CO)3(η
6-C6H5){Co2(CO)6-η
2-μ
2-C≡C–}–C6H4–Fc] (2) and [Cr(CO)3(η
6-C6H5){Co2(CO)6-η
2-μ
2-C≡C–}Fc–C(CH3)2–Fc] (4) were obtained. Four carbonyl complexes were characterized by elemental analysis, FT-IR, NMR and MS. The molecular structures
of complexes (1), (2) and (4) were determined by single crystal X-ray diffraction. The interactions among the ferrocenyl,
Cr(CO)3 and Co2(CO)6-η
2-μ
2-C≡C– units were investigated by cyclic voltammetry. 相似文献
9.
Sumitava Khan Subhasis Roy Kishalay Bhar Partha Mitra Alexandra M. Z. Slawin Barindra Kumar Ghosh 《Transition Metal Chemistry》2011,36(1):99-106
Two hexacoordinated mononuclear Co(III) compounds of the type cis-[Co(L)(N3)2] X [1, X = ClO4; 2, X = PF6; L = N,N′-(bis(pyridine-2-yl)benzylidine)-1,4-butanediamine] have been synthesized and characterized by physicochemical and spectroscopic
methods. The crystal structures of complexes 1 and 2 both have distorted octahedral geometry with two terminal azides in mutual cis orientations. In the crystalline state, two
mononuclear units of 1 are associated by weak C–H…π interactions to produce a dimeric unit, which packs through C–H…O hydrogen bonds and π…π interactions
leading to a 2-D continuum. The mononuclear units in 2 are engaged in weak cooperative intermolecular C–H…π interactions and multiple C–H…F hydrogen bonds giving rise to a 3-D
network structure. These diamagnetic compounds are redox active and show luminescence in DMF solutions. 相似文献
10.
The reaction of [PtMe3(bpy)(Me2CO)](BF4) (2) (prepared from [PtMe3I(bpy)] (1) plus Ag(BF4)) with MeSSMe resulted in the formation of [PtMe3(bpy)(MeSSMe-κS)](BF4) (3). A single-crystal X-ray diffraction analysis revealed in the octahedral Pt(IV) complex (configuration index: OC-6-33), a conformation of the monodentately κS bound MeSSMe ligand (C–S–S–C 92.7(4)°) being very close to that in non-coordinated MeSSMe, thus allowing some hyperconjugative
interaction stabilizing the S–S bond. The reaction of [K(18C6)][(PtMe3)2(μ-I)(μ-pz)2] (4; 18C6 = 18-crown-6, Hpz = pyrazole) with Ag(BF4) and MeSSMe resulted in the formation of dinuclear complexes [(PtMe3)2(μ-pz)2(μ-MeSSMe)] existing at room temperature in acetone solution as different fast interconverting isomers. At –40 °C, two isomers
with a μ-1κS:2κS (5a) and a μ-1κS:2κS′ (5b) coordinated MeSSMe ligand in the ratio 2:1 could be identified 1H NMR spectroscopically. DFT calculations of type 5 complexes revealed the existence of two conformers with a μ-MeSSMe-1κS:2κS ligand, which differ mainly in the C–S–S–C dihedral angle (66.4 vs. 180.0° 6a/6a′). They have essentially the same energy and a very low activation barrier in acetone as solvent (1.3 kcal/mol) for their
mutual interconversion. A further equilibrium structure was identified to be an isomer having a μ-MeSSMe-1κS:2κS′ ligand (6b) that proved to be only 1.9 kcal/mol higher in energy than 6a/6a′. 相似文献
11.
Khodayar Gholivand Farzaneh Afshar Zahra Shariatinia Karim Zare 《Structural chemistry》2010,21(3):629-636
Abstract
New phosphoramidates with formula 3-NC5H4C(O)NHP(O)XY (X=Y=Cl (1), X=Y=NH–C(CH3)3 (2a,2b), X=Y=N(C4H9)2 (3), X=Cl, Y=N(C2H5)2 (4) were synthesized and characterized by IR, 1H-, 13C-, 31P-NMR spectroscopy and CHN elemental analysis. Surprisingly, the reaction of compound 2a with LaCl3, 7H2O in 3:1 M ratio leads to a polymorph of this compound (2b). NMR spectra indicate that 2 J(PNHamide) in 2b (7.0 Hz) is very much greater than in 2a (4.1 Hz), while δ(31P) values are identical for both of them. In IR spectra, υ(P=O) is weaker but υ(C=O) is stronger in 2a than in 2b. The structures of 2a, 2b were determined by X-ray crystallography. These compounds form centrosymmetric dimers via two intermolecular P=O……H–N hydrogen bonds. Strong intermolecular N–H…N, N–H…O and weak C–H…O hydrogen bonds lead to a three-dimensional polymeric cluster in the 2a while intermolecular strong N–H……N and weak C–H……O hydrogen bonds form a two-dimensional polymeric chain in 2b. 相似文献12.
Abstract
Four complexes of 3,3-diphenylpropanoate (L) and 4,4′-bipyridine as auxiliary bridging ligands were synthesized and characterized, namely [Zn(L)2(4bpy)(EtOH)2]∞ (1), [Co(L)2(4bpy)(EtOH)2]∞ (2), [Ni(L)2(4bpy)(EtOH)2]∞ (3), and [Cu(L)2(4bpy)(H2O)]∞ (4) (4bpy = 4,4′-bipyridine). X-ray single-crystal diffraction analyses show that complexes 1–4 all take one-dimensional (1D) fishbone-like structures incorporating bridging 4bpy ligands. The complexes show different supramolecular frameworks interlinked via intermolecular hydrogen bonds, π···π stacking, and/or C–H···π supramolecular interactions. Complex 3 only has a simple one-dimensional fishbone-like chain, whereas complexes 1 and 2 show two-dimensional supramolecular structures by interchain C–H···O hydrogen bonds. Complex 4 is assembled into two-dimensional layers and then an overall three-dimensional framework by a combination of interchain O–H···O hydrogen bonds and C–H···π supramolecular interactions. The luminescent properties of the ligands and their complexes were investigated. 相似文献13.
Jin-Zhong Gu Dong-Yu Lv Zhu-Qing Gao Jian-Zhao Liu Wei Dou 《Transition Metal Chemistry》2011,36(1):53-58
Three Co(II) and Ni(II) complexes, namely [Co(bpdc)(H2O)2] (1), [Ni(bpdc)(H2O)2] (2), and [Co2(bpdc)2(prz)0.5(H2O)3]·0.5H2O (3) (H2bpdc = 2,2′-bipyridine-6,6′-dicarboxylic acid and prz = piperazine), have been synthesized from H2bpdc and the corresponding metal salts under hydrothermal conditions. The complexes were characterized by physico-chemical
and spectroscopic methods, as well as by X-ray crystallography. Compounds 1 and 2 both consist of neutral mononuclear molecules, of [Co(bpdc)(H2O)2] and [Ni(bpdc)(H2O)2], respectively. Compound 3 consists of a mononuclear molecule of [Co(bpdc)(H2O)2] and a binuclear molecule of [Co2(bpdc)2prz (H2O)2]. The discrete neutral complexes 1–3 further extend their structures into three-dimensional supramolecular architectures by intermolecular O–H⋯O and C–H⋯O hydrogen
bonds as well as π–π stacking interactions. Magnetic susceptibility measurements show that complex 3 exhibits weak ferromagnetic interactions between the two Co(II) ions bridged by the prz ligand, with C = 5.41 cm3 mol−1 K and θ = +27.6 K, respectively. 相似文献
14.
Two new neodymium complexes, [Nd2(abglyH)6(2,2′-bipy)2(H2O)2] · 4H2O 1 and {[Nd(abglyH)3(H2O)2] · (4,4′-bipy) · 7H2O}n
2 (abglyH2 = N-P-acetamidobenzenesulfonyl-glycine acid, 2,2′-bipy = 2,2′-bipyridine, 4,4′-bipy = 4,4′-bipyridine), have been synthesized and
their structures have been measured by X-ray crystallography. In 1, nine-coordinated Nd(III) ions are bridged by two syn–syn bidentate and two tridentate bridging carboxylate groups from four different abglyH− anions to form dinuclear motifs, which are further connected into a 3-D supramolecular framework via hydrogen bonds between
the binuclear motifs and the uncoordinated water molecules. In 2, eight-coordinated Nd(III) ions are linked by six carboxylate groups adopting a syn–syn bidentate bridging fashion to form a 1-D inorganic–organic alternating linear chain. These polymeric chains generate microchannels
extending along the a direction, and these cavities are occupied by discrete tetradecameric water clusters, which interact with their surroundings
and finally furnish the 3-D supramolecular network via hydrogen bonds. At the same time, π–π stacking interactions between
benzene rings from abglyH− anions also play an important role in stabilizing the network. 相似文献
15.
The geometrical structure and conformation of dimethyloxalate, CH3OC(O)–C(O)OCH3, have been studied by gas electron diffraction (GED) and quantum-chemical calculations (MP2 and B3LYP methods with 6-31G* and cc-pVTZ basis sets). The GED analysis with a dynamic model (T = 323 K) results in a mixture of two planar conformers, anti (C2h symmetry) and syn (C2v symmetry) orientation of the two C=O bonds. The energy difference between these conformers is 0.02(0.18) kcal/mol and barrier to internal rotation around the C–C bond is 0.44(0.41) kcal/mol. The CH3 groups occupy synperiplanar positions with respect to the C=O bonds. The following main geometrical parameters for the anti conformer (Å and degrees) have been derived: rg(C–C) = 1.532(3), rg(C=O) = 1.203(2), rg(Csp3–O) = 1.436(3), rg(Csp2–O) = 1.333(3), (Csp2–Csp2–O) = 111.9(1.9), (Csp2–O–Csp3) = 116.3(1.6), (O–C= O) = 127.0(1.8).This paper is devoted to the 75th anniversary of gas electron diffraction method. 相似文献
16.
Jian-Long Xia Wei-Cheng Xiong Gang Chen Guang-Ao Yu Shan Jin Sheng-Hua Liu 《Transition Metal Chemistry》2009,34(4):389-393
Abstract Formal [2 + 2 + 2] addition reaction of [Cp*Ru(H2O)(NBD)][BF4] (NBD = norbornadiene) with 4,4′-Diethynylbiphenyl generates [C9H9-η6-C6H4(RuCp*)–C6H4(RuCp*)-η6-C9H9][BF4]2. The reaction of [Cp*Ru(H2O)(NBD)][BF4] with 1,4-diphenylbutadiyne generates the unusual [2 + 2 + 2] additional organic compound Ph–C≡C–C9H8–Ph in addition to the organometallic compound [Cp*Ru(η6-C6H5–C≡C–C≡C–Ph)][BF4]. [C9H9-η6-C6H4(RuCp*)–C6H4(RuCp*)-η6-C9H9][BPh4]2 is generated after the reaction of compound [C9H9-η6-C6H4(RuCp*)–C6H4(RuCp*)-η6-C9H9][BF4]2 with Na[BPh4]. The structure of this compound was confirmed by X-ray diffraction. A possible approach to form Ph–C≡C–C9H8–Ph and [Cp*Ru(η6-C6H5–C≡C–C≡C–Ph)][BF4] is suggested.
Graphical Abstract Formal [2 + 2 + 2] addition reaction of [Cp*Ru(H2O)(NBD)]BF4 (NBD = norbornadiene) with 4,4′-Diethynylbiphenyl generates [C9H9-η6-C6H4(RuCp*)–C6H4(RuCp*)-η6-C9H9][BF4]2. The reaction of [Cp*Ru(H2O)(NBD)][BF4] with 1,4-diphenylbutadiyne simply generates unusual [2 + 2 + 2] additional organic compound Ph–C≡C–C9H8–Ph in addition to the organometallic compound [Cp*Ru(η6-C6H5–C≡C–C≡C–Ph)][BF4]. [C9H9-η6-C6H4(RuCp*)–C6H4(RuCp*)-η6-C9H9][BPh4]2 is generated after the reaction of compound [C9H9-η6-C6H4(RuCp*)–C6H4(RuCp*)-η6-C9H9][BF4]2 with Na[BPh4]. The structure of this compound was confirmed by X-ray diffraction. And the possible approach to form Ph–C≡C–C9H8–Ph and [Cp*Ru(η6-C6H5–C≡C–C≡C–Ph)][BF4] was suggested.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献
17.
Zhi Qiang Shi Ning Ning Ji Ren Gao Zhao Ji Kun Li Zhi Feng Li 《Structural chemistry》2011,22(1):225-233
Two new copper(II) complexes, [Cu(p-FBA)2(2,2′-bpy)]·(H2O) (1) and [Cu(p-FBA)(2,2′-bpy)2]·(p-FBA)2 (2) {p-FBA = p-fluorobenzoic acid, 2,2′-bpy = 2,2′-bipyridine} have been obtained from an identical starting mixture using temperature as
the only independent variable and characterized by X-ray single crystal diffraction as well as with infrared spectroscopy,
elemental analysis, and thermogravimetric analysis. The results reveal that 1 has 1D infinite chain structure formed by O–H···O hydrogen bonds, while 2 features a 0D structure. Additionally, there exist C–H···O hydrogen bonds and π–π stacking interactions in 1, forming 2D supramolecular structure. Furthermore, density functional theory (DFT) calculations of the structures, stabilities,
orbital energies, composition characteristics of some frontier molecular orbitals and Mulliken charge distributions of the
[Cu(p-FBA)2(2,2′-bpy)] of 1 and [Cu(p-FBA)(2,2′-bpy)2]+ cation of 2 were performed by means of Gaussian 03W package and taking B3LYP/lanl2dz basis set. 相似文献
18.
Chun-Sen Liu E. Carolina Sañudo Li-Fen Yan Ze Chang Jun-Jie Wang Tong-Liang Hu 《Transition Metal Chemistry》2009,34(1):51-60
Abstract To explore the influence of the anthracene ring skeleton, with a large conjugated π-system, on the structures and properties
of its complexes, two MnII complexes with anthracene-9-carboxylate ligand were synthesized and structurally characterized: {[Mn(L)2(H2O)2](H2O)}∞ (1) and [Mn2(L)4(phen)2(μ-H2O)](CH3OH) (2) (L = anthracene-9-carboxylate and phen = 1,10-phenanthroline). Complex (1) has a one-dimensional (1D) chain structure that is further assembled to form a two-dimensional (2D) sheet, and then an overall
three-dimensional (3D) network by π···π stacking and/or C–H···π interactions. Complex (2) makes a dinuclear structure by incorporating the chelating phen ligand, which is further interlinked via inter-molecular
π···π stacking and C–H···π interactions to generate a higher-dimensional supramolecular network along the different crystallographic
directions. The results reveal that the bulky anthracene ring skeleton in L, by virtue of intra- and/or inter-molecular π···π
stacking and C–H···π interactions, plays an important role in the formation of complexes (1) and (2). The magnetic properties of (1) and (2) were further investigated. As expected, the very long inter-metallic separations result in weak magnetic coupling, with
the corresponding coupling constant values of J = −10 cm−1 for (1) and J = −2.46 cm−1 for (2).
Graphical abstract The constructions of two new MnII complexes comprising 1D chain (1) and dinuclear subunit (2) structures have been successfully achieved by using a bulky anthracene-9-carboxylic acid (HL), together with incorporating
the chelating 1,10-phenanthroline as a co-ligand for (2). The result reveals that the bulky anthracene ring skeleton of HL, by virtue of intra- and/or inter-molecular π···π stacking
and C–H···π interactions, plays an important role in the formation of the supramolecular architectures of (1) and (2). Moreover, magnetic properties of the complexes have been investigated.
相似文献
19.
Thermal behavior of xGa2O3–(50 − x)PbO–50P2O5 (x = 0, 10, 20, and 30 mol.% Ga2O3) and xGa2O3–(70 − x)PbO–30P2O5 (x = 0, 10, 20, 30, and 40 mol.% Ga2O3) glassy materials were studied by thermo-mechanical analysis (TMA) and differential thermal analysis (DTA). Replacement of
PbO for Ga2O3 is accompanied by increasing glass-transition temperature (263 ≤ T
g/°C ≤ 535), deformation temperature (363 ≤ T
d/°C ≤ 672), crystallization temperature (396 ≤ T
c/°C ≤ 640) and decreasing of coefficient of thermal expansion (5.1 ≤ CTE/ppm K−1 ≤ 16.7). Values of Hruby parameter were determined (0.1 ≤ K
H ≤ 1.3). The thermal stability of prepared glasses increases with increasing of concentration of Ga2O3. 相似文献
20.
Wen-Kui Dong Jun-Feng Tong Yin-Xia Sun Jian-Chao Wu Jian Yao Shang-Sheng Gong 《Transition Metal Chemistry》2010,35(4):419-426
Two new mono- and dinuclear Cu(II) complexes, namely [CuL1]·0.5H2O (1) and [(Cu2(L2)2)(DMF)]·0.5DMF (2) (H2L1 = 1,2-bis{[(Z)-(3-methyl-5-oxo-1-phenyl-1H-pyrazolidin-4(4H)-yl)(phenyl)]methylene-aminooxy}ethane; H2L2 = 1,3-bis{[(Z)-(3-methyl-5-oxo-1-phenyl-1H-pyrazolidin-4(4H)-yl)(phenyl)] methyleneaminooxy}propane), have been synthesized and characterized by X-ray crystallography. The unit cell
of complex 1 contains two crystallographically independent but chemically identical [CuL1] molecules and one crystalline water molecule, showing a slightly distorted square-planar coordination geometry and forming
a wave-like pattern running along the a-axis via hydrogen bonding and π···π stacking interactions. Complex 2 has a dinuclear structure, comprising two Cu(II) atoms, two completely deprotonated phenolate bisoxime (L2)2− moieties (in the form of enol), and both coordinated and hemi-crystalline DMF molecules. Complex 2 has square-planar and square-pyramidal geometries around the two copper centers, whose basic coordination planes are almost
perpendicular and form an infinite three-dimensional supramolecular network structure involving intermolecular C–H···N, C–H···O,
and C–H···π(Ph) hydrogen bonding and π···π stacking interactions of neighboring pyrazole rings. 相似文献