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1.
Arturo Arduini Francine F. Nachtigall Andrea Pochini Andrea Secchi Franco Ugozzoli 《Supramolecular chemistry》2013,25(3):273-291
Abstract To gain information on CH-π aromatic interactions involved in the formation of host-guest adducts, the geometrical parameters which define the solid state structures of the complexes of calix[4]arenes in the cone conformation with guests having acid CH3 or CH2 groups have been studied. Most of the data have been obtained from the CH3CN and CH2Cl2 calix[4]arene complexes retrieved from the literature. To understand the effect of the acidity on these parameters, p-cyclohexylcalix[4]arene-biscrown-3 ? CH3CN, p-tert-butylthiacalix[4]arene ? CH3CN, p-tert-butylthiacalix[4]arene ? CH3NO2, 1,3-dipropoxy-p-tert-butylcalix[4]arene ? ClCH2CN and 1,3-dipropoxy-p-tert-butylcalix[4]arene ? CH2(CN)2 complexes were prepared, crystallised and investigated in the solid state. CH3X guests are bound preferentially by hosts having a C4 symmetry. The interaction is directional, but it is independent from the basicity of the host and acidity of the guest, indicating that classic hydrogen bond do not play a major role. On the contrary CH2XY guests find the best matching with hosts having a C2v symmetry, interacting specifically with two diametrical aromatic rings. These interactions are directional and show a correlation between the acidity of the guest and the CH-π aromatic distance, thus supporting a stronger contribution of “classic” hydrogen bond in these latter complexes. These results are in agreement with the hypothesis that CH-π aromatic interactions derive from the superimposition of different types of intermolecular forces, whose contribution depends on several factors as the nature of the interacting partners. 相似文献
2.
Oleg V. Surov Nugzar Zh. Mamardashvili Gennadiy P. Shaposhnikov Oskar I. Koifman 《Journal of inclusion phenomena and macrocyclic chemistry》2007,58(3-4):329-335
The inclusion of small neutral organic guests (C6H14, CH2Cl2, CH3OH) by calix[4]arene receptors was found by 1H NMR spectroscopy and microanalysis. The studied calix[4]arenes can form stable intramolecular complexes with solvent molecules
which keep the stoichiometric composition without changing under conditions of the sublimation experiment. The saturated vapour
pressures of calix[4]arenes and complexes of calix[4]arenes with solvent molecules were determinated for the first time by
the Knudsen’s effusion method in the wide temperature range. The changing of standard thermodynamic parameters of complexation
by transfer process from condensed state to vapour phase was estimated. It was shown that the large flexibility of the calixarene
ligand structure corresponds to a strongly negative entropic contribution as well as negative enthalpy term to the Gibbs energy
of formation of host–guest complexes in the gas phase. 相似文献
3.
The Cerium(IV) complexes [{N[CH2CH2N=CH(2‐O‐3,5‐tBu2C6H2)]3}CeCl] ( 1 ) and [{N[CH2CH2N=CH(2‐O‐3,5‐tBu2C6H2)]3}Ce(NO3)] ( 2 ) were derived from the condensation of tris(2‐aminoethyl)amine and 3,5‐di‐tert‐butylsalicylaldehyde and the appropriate Ce starting material CeCl3(H2O)6 and (NH4)2[Ce(NO3)6], respectively. Single crystal X‐ray diffraction studies reveal monomeric complexes. 相似文献
4.
Ma del Carmen Fernández-Fernández Alejandro Macías Laura Valencia 《Journal of organometallic chemistry》2009,694(22):3608-3613
The coordination capability of the new tetrapyridyl pendant-armed azamacrocyclic ligand L, towards Co(II), Ni(II), Cu(II) and Cd(II) ions was studied. The ligand and the complexes were characterized by microanalysis, LSI mass spectrometry, IR, UV-Vis and NMR spectroscopy, magnetic studies and conductivity measurements. Crystal structures of [Co2L(CH3CN)2](ClO4)4·2CH3CN and [Cd2L(NO3)2](NO3)2·2H2O complexes have been determined. The X-ray studies show the presence of dinuclear endomacrocyclic complexes with the metal ion in a similar distorted octahedral environment, coordinated by one pyridyl bridgehead group, two amine nitrogen atoms and two pyridyl pendant-arms. The sixth coordination position around the metal ion is completed by one acetonitrile molecule in [Co2L(CH3CN)2](ClO4)4·2CH3CN and by one monodentate nitrate anion in [Cd2L(NO3)2](NO3)2·2H2O. Different sort of intramolecular non-classical hydrogen bonds were found in the crystal lattice of both structures. 相似文献
5.
D. Ballivet-Tkatchenko A. Boughriet C. Bremard 《Journal of Electroanalytical Chemistry》1985,196(2):315-327
Electrochemical investigations of the reduction of dicationic, monocationic and neutral dinitrosyl molybdenum complexes in nitromethane and acetonitrile are reported. All the compounds with the general formulae: [Mo(NO)2L2L′2]2+, [Mo(NO)2L2L′Cl]+ and Mo(NO)2L2Cl2 (L = CH3CN, CH2CHCN, C6H5CN, C5H5N, P(C6H5)3, L2 = 2,2′-bipyridine, L′ = CH3CN and L′2 = 2,2′-bipyridine) are reducible by one electron to yield 19-electron complexes. The dicationic complexes undergo a reversible one-electron transfer. For the mono- and dichlorocomplexes, the one-electron transfer induces the facile exchange of the chloroligand in the 19-electron complexes except for L2 = 2,2′-bipyridine. However, the exchange of the chloroligand is followed by the fast anation by Cl? of the remaining 18-electron chlorocomplexes to afford [Mo(NO)2Cl3L]? and [Mo(NO)2Cl4]2? which are reducible at higher negative potentials than dichloro- and monochlorocomplexes. The multiple electrochemical step system is not catalytic, but of the electroactivation type. 相似文献
6.
Bruce N. Storhoff Daniel P. Harper Ivan H. Saval Jonathan H. Worstell 《Journal of organometallic chemistry》1981,205(2):161-166
Both (C6H5)2P(CH2)3CN and (C6H5)2P(CH2)4CN have been obtained from the reaction of Br(CH2)nCN (n = 3, 4) with (C6H5)2POCH3 followed by reduction with (C6H5)2SiH2. These phosphine-nitrile ligands form L2PdCl2 complexes which are shown by IR measurements to have trans geometries with the phosphine portions of the ligands coordinated. Reactions of o-BrC6H4CN with CH3(CH2)3Li followed by R2PCl (R = C6H5 or (CH3)2N) have been used to provide good yields of the corresponding R2P-o-C6H4CN products. 相似文献
7.
The complexes [PtR2L2] and [PtR(Cl)L2] containing phosphines (L) and the σ-carbyl ligands R (R CH2NO2, CCPh, CH2CN, CH2COPh, CH2COC6H4NO2-4, CH2COC6H4OMe-2, CH2COMe) have been prepared from [PtCl2L2], RH and KOH in the presence of 18-crown-6. Some complexes containing hydroxo-ligands were also formed. Structures have been determined from the 31P-{1H} and 1H NMR spectra. 相似文献
8.
Jesús Martínez Laura Valencia Rufina Bastida David E. Fenton Sharon E. Spey Alejandro Macías 《无机化学与普通化学杂志》2002,628(5):1059-1067
The pendant‐armed ligands L1 and L2 were synthesized by N‐alkylation of the two secondary aminic groups of the oxaazamacrocyclic precursor L with o‐nitrobenzylbromide (L1) or p‐nitrobenzylbromide (L2). Metal complexes of L1 and L2 have been synthesized and characterized by microanalysis, MS‐FAB, conductivity measurements, IR, UV‐Vis, 1H and 13C NMR spectroscopy and magnetic studies. Crystal structures of ligands L1 and L2, as well as complexes [CdL1(NO3)2]·2CH3CN and [Ag2Br(L2)2](ClO4)·2CH3CN have been determined by single crystal X‐ray crystallography. 相似文献
9.
Višnja Vrdoljak Prof. Dalibor Milić Marina Cindrić Dubravka Matković‐Čalogović Jana Pisk Marina Marković Predrag Novak 《无机化学与普通化学杂志》2009,635(8):1242-1248
New dinuclear pentacoordinate molybdenum(V) complexes, [Mo2VO3L2] [L = thiosemicarbazonato ligand: C6H4(O)CH:NN:C(S)NHR′ and C10H6(O)CH:NN:C(S)NHR′; R′ = H, CH3, C6H5) were obtained either by oxygen atom abstraction from MoVIO2L with triphenylphosphine or by using [Mo2O3(acac)4] in the reaction with the corresponding ligands H2L. Crystal and molecular structure of [Mo2O3{C6H4(O)CH:NN:C(S)NHC6H5}2] · CH3CN has been determined by the single‐crystal X‐ray diffraction method. 相似文献
10.
Binyuan Liu Chunying Tian Li Zhang Weidong Yan Wenjun Zhang 《Journal of polymer science. Part A, Polymer chemistry》2006,44(21):6243-6251
A series of LZnX zinc/β‐ketoiminato complexes [L = CH3C(OH)?C(CH2CH?CH2)C(CH3)?NAr ( L1 ), CH3C(OH)?C(CH2CH2CN)C(CH3)?NAr ( L2 ), CH3C(OH)?C(CH2C6H5)C(CH3)?NAr ( L3 ), or CH3C(OH)?CHC(CH3)?NAr ( L4 ); Ar = 2,6‐iPr2C6H3; and initiation group X = alcoholate or acetate (for L1 ) or alcoholate (for L2 – L4 )] were synthesized, and their activities toward the copolymerization of carbon dioxide with cyclohexene oxide were determined. The 3‐position substituents on the β‐ketoiminato ligand backbone of the zinc/β‐ketoiminato complexes played an important role not only in the catalytic activity but also in the intrinsic viscosity, chemical composition, and refined microstructure of the resultant copolymers. The order of the catalytic activity of L1 ZnX with different initiation groups (X = OMe, OiPr, or OAc) was L1 Zn (OiPr) > L1 Zn (OMe) > L1 Zn (OAc), being the opposite of the order of the leaving ability of the initiation groups. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 6243–6251, 2006 相似文献
11.
Montserrat Lpez‐Deber Rufina Bastida Maria del Carmen Fernndez‐Fernndez Alejandro Macías Adolfo Rodríguez Laura Valencia 《无机化学与普通化学杂志》2005,631(11):2033-2040
A new mixed oxaaza‐macrocyclic ligand, L1, has been obtained by direct synthesis between 1,4‐bis‐(2′‐formylphenyl)‐1,4‐dioxabutane and the diamine 2,2′‐ethylenedioxydiethylamine. The dialkylated ligand L2, bearing two nitrobenzyl pendant groups, has been prepared and transitional, post‐transitional and Ca2+, Sr2+, and Ba2+ metal complexes have been synthesized in order to elucidate the coordination preferences. The crystal structures of the ligands L1 and L2 and the complexes [SrL2(H2O)2](ClO4)2 and [BaL2(NCS)2(CH3CN)]·CH3CN have been determined by single crystal X‐ray diffraction. The structures reveal the presence of mononuclear endomacrocyclic complexes where the pendant arms radiate away from the ligand. 相似文献
12.
Zhichao Zhang Dongmei Cui Xinli Liu 《Journal of polymer science. Part A, Polymer chemistry》2008,46(20):6810-6818
The syntheses of several dialkyl complexes based on rare‐earth metal were described. Three β‐diimine compounds with varying N‐aryl substituents (HL1=(2‐CH3O(C6H4))N?C(CH3)CH?C(CH3)NH(2‐CH3O(C6H4)), HL2 = (2,4,6‐(CH3)3 (C6H2))N?C(CH3)CH?C(CH3)NH(2,4,6‐(CH3)3(C6H2)), HL3 = PhN?C(CH3)CH(CH3) NHPh) were treated with Ln(CH2SiMe3)3(THF)2 to give dialkyl complexes L1Ln (CH2SiMe3)2 (Ln = Y ( 1a ), Lu ( 1b ), Sc ( 1c )), L2Ln(CH2SiMe3)2(THF) (Ln = Y ( 2a ), Lu ( 2b )), and L3Lu(CH2SiMe3)2(THF) (3). All these complexes were applied to the copolymerization of cyclohexene oxide (CHO) and carbon dioxide as single‐component catalysts. Systematic investigation revealed that the central metal with larger radii and less steric bulkiness were beneficial for the copolymerization of CHO and CO2. Thus, methoxy‐modified β‐diiminato yttrium bis(alkyl) complex 1a , L1Y(CH2SiMe3)2, was identified as the optimal catalyst, which converted CHO and CO2 to polycarbonate with a TOF of 47.4 h?1 in 1,4‐dioxane under a 15 bar of CO2 atmosphere (Tp=130 °C), representing the highest catalytic activity achieved by rare‐earth metal catalyst. The resultant copolymer contained high carbonate linkages (>99%) with molar mass up to 1.9 × 104 as well as narrow molar mass distribution (Mw/Mn = 1.7). © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 6810–6818, 2008 相似文献
13.
The complexes XAu(C6F5)2AsPh3 have been prepared by substitution of chloro- or perchlorato-bis(pentafluorophenyl)triphenylarsinegold(III) with alkali or with silver salts MX (X = NO3, CH3COO, NO2, CF3COO, CN, SCN, N3 and C6H5COO). Decomposition of the nitrato or acetato complex leads to C6F5AuAsPh3. 相似文献
14.
The (hydroxo) methyl complex Pt(OH)(CH3)(Diphos) [Diphos = Ph2PCH2CH2PPh2] reacts with compounds containing acidic CH bonds (HX) to give unsymmetrical cis-dialkyls of general formula Pt(CH3)X(Diphos) [X = CH2COCH3, CH(COCH3)2, CH2CN or CH2NO2]; both the methyl and the cyclohexenyl complexes Pt(OH)R(Diphos) (R = CH3 or C6H9) insert carbon monoxide to give hydroxycarbonyl complexes PtR(CO2H)(Diphos) which are remarkably stable to decomposition by β-elimination. 相似文献
15.
《Journal of organometallic chemistry》2005,690(24-25):6041-6050
Reaction of [Ag(CH3impy)2]PF6, 1, with Au(tht)Cl produces the monometallic Au(I)-species [Au(CH3impy)2]PF6, 2. Treatment of 2 with excess AgBF4 in acetonitrile, benzonitrile or benzylnitrile produces the polymeric species {[AuAg(CH3impy)2(L)](BF4)2}n, (L = CH3CN,3; L = C6H5CN, 4; L = C6H5CH2CN, 5) where the Au(I) centers remain bound to two carbene moieties while the Ag(I) centers are coordinated to two alternating pyridyl groups and a solvent molecule (L). Reaction of 2 with AgNO3 in acetonitrile produces the zig-zag mixed-metal polymer {[AuAg(CH3impy)2(NO3)]NO3}n, 6, that contains a coordinated nitrate ion in place of the coordinated solvent species. All of these polymeric materials are dynamic in solution and dissociate into their respective monometallic components. Compounds 2–6 are intensely luminescent in the solid-state and in frozen solution. All of these complexes were characterized by 1H, 13C NMR, electronic absorption and emission spectroscopy and elemental analysis. 相似文献
16.
Synthesis and Characterization of β‐Diketiminate Aluminum Compounds and Their Use in the Ring‐Opening Polymerization of ε‐Caprolactone
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Xiaoli Ma Miaomiao Yao Mingdong Zhong Ziyan Deng Wenling Li Zhi Yang Herbert W. Roesky 《无机化学与普通化学杂志》2017,643(2):198-202
Four aluminum alkyl compounds, [CH{(CH3)CN‐2,4,6‐MeC6H2}2AlMe2] ( 1 ), [CH{(CH3)CN‐2,4,6‐MeC6H2}2AlEt2] ( 2 ), [CH{(CH3)CN‐2‐iPrC6H4}2AlMe2] ( 3 ), and [CH{(CH3)CN‐2‐iPrC6H4}2AlEt2] ( 4 ), bearing β‐diketiminate ligands [CH{(Me)CN‐2,4,6‐MeC6H2}]2 (L1H) and [CH{(Me)CN‐2‐iPrC6H4}]2 (L2H) were obtained from the reactions of trimethylaluminum, triethylaluminum with the corresponding β‐diketiminate, respectively. All compounds were characterized by 1H NMR and 13C NMR spectroscopy, single‐crystal X‐ray structural analysis, and elemental analysis. Compounds 1 – 4 were found to catalyze the ring‐opening polymerization (ROP) of ε‐caprolactone (ε‐CL) with good activity. 相似文献
17.
The thermal decomposition of the complexes trans-[Pt(X)(CH3)L2] (L P(C2H5)3; X Cl, Br, I, CN) in decalin at 170 and 200°C affords methane platinum metal and [Pt(X)2L2]. The kinetics of the decomposition of the complexes were determined by monitoring the appearance of methane by GLC. The observed first-order rate constant was found to be independent on the nature of the ligand X. The thermal decomposition of the trideuteriomethyl complexes [Pt(X)(CD3)L2] (X I, CN) in decalin-d18 at 170 and 200°C was studied by GLC/MS. The thermolysis affords CD3H and CD4 in ratios which are independent of the nature of X and of the temperature used. The mass spectra of the complexes were also examined. A relative scale of platinum-to-methyl bond dissociation energies has been established by measuring the appearance potential of the fragment ion [Pt(X)L2]+ and the ionization energies in the series [Pt(X)(CH3)L2]. Ionization potentials and PtCH3 bond energies show a clear dependence on the nature of X which is not reflected in corresponding changes in the decomposition rates. 相似文献
18.
Shyamapada Shit Soma Sen Samiran Mitra David L. Hughes 《Transition Metal Chemistry》2009,34(3):269-274
Two new square-planar Ni(II) complexes, [NiL1(NCS)] (1) and [NiL2(N3)] (2) have been synthesized with the unsymmetrical tridentate Schiff base ligands [(CH3)2NCH2CH2N=C(CH3)CH=C(OH)(C6H5)], L
1
H, derived from benzoylacetone and 2-dimethylaminoethylamine and [(CH3CH2)2NCH2CH2N=C(CH3)CH=C(OH)(C6H5)], L
2
H, derived from benzoylacetone and 2-diethylaminoethylamine, respectively. The complexes have been characterized by elemental
analysis, FT-IR, UV-Vis spectroscopy, electrochemical and thermal methods (where applicable). Structures have been established
by the single-crystal X-ray diffraction technique which reveals the discrete nature of the complexes in which the metal centers
adopt a distorted square planar geometry. Coordination environments of the metal ions in the complexes are satisfied with
two different unsymmetrical Schiff base ligands having similar N2O donor sets and a terminal pseudohalide anion (thiocyanate for 1 and azide for 2). 相似文献
19.
Phenol, having favourable physical and chemical properties, can be enclosed as the guest component in the clathrates of tetracyano complexes. Six compounds of Hofmann and similar type clathrates M(NH3)2M' (CN)4.nG and M(en)m M'(CN)4.nG were prepared and identified: Ni(NH3)2Pt.2C6H5OH; Ni(en)2Pt(CN)4.O.14C6H5OH; Ni(NH3)2Pt(CN)4.C6H5OH.H2O; Zn(NH3)2Ni(CN)4.O.1C6H5OH.H2O; Cu(NH3)2Ni(CN)4. 2C6H5OH and Fe(NH3)2Ni(CN)4.2C6H5OH. The phenol containing clathrates are more stable than clathrates containing other guest molecules. In the case of Ni(en)2 Pt(CN)4.O.14C6H5OH thermal loss of the guest molecule leaves the host lattice intact, but further heating results in the rupture of the host lattice. The compounds were capable in the solid state of sorbing other organic molecules once they had been heated to the temperature required for almost complete loss of guest molecule i.e. n→o. 相似文献
20.
《Journal of organometallic chemistry》1986,303(3):417-427
Further studies of the reactions between ruthenium σ-acetylide complexes and electrophilic olefins CHArC(CN)(X) (Ar = C6H4NO2-4, Ph; X = CN; Ar = C6H4NO2-4, X = CO2Et) have shown the formation of allylic, butadienyl, and in one case, cyclobutenyl complexes. The direction of addition is such that the =C(CN)(X) group becomes attached to the α-carbon of the acetylide. This is confirmed by the X-ray structure of Ru{C[C(CN)2]CPhCH(C6H4NO2-4)}(dppe)(η-C5H5) · 0.5CH2Cl2, cr with cell dimensions a 28.81(1), b 9.661(2), c 30.782(8) Å, β 95.02 (3)°, and Z = 8. The structure was refined by a least-squares procedure with the use of 4291 statistically significant reflections [I > 2.5σ(I)] to R 0.075 and Rw 0.076. 相似文献