Synthesis,GC-EIMS,~1H NMR,~(13)C NMR,Mechanistic and Thermal Studies of o-Xylylene-α,α'-bis (triphenylphosphinebromide)

Organophosphorous compounds containing phosphorus as an integral part have been widely used in industry, organic synthesis and optoelectronics. o-Xylylene-α,α'-bis(triphenylphosphinebromide)(OXBTPPB) is a facile reagent to convert o-quinones(e.g., 9,10-phenanthrenequinone) into polycyclic aromatic hydrocarbons(PAHs). Herein lies an improved synthetic route to OXBTPPB. The resultant was carefully characterized with GC-EIMS, 1H NMR, 13C NMR, spectroscopic techniques. The EIMS shows characteristic peaks at m/z...     

A Direct Carbon-13 and Nitrogen-15 NMR Study of Cerium(III)–Isothiocyanate Complexation in Aqueous Solvent Mixtures

A study of lanthanide complexation with isothiocyanate is underway using a multinuclear magnetic resonance technique. For isothiocyanate solutions in water–acetone–Freon mixtures at low temperature, –85––125°C, ligand exchange is slow enough to permit the observation of ¹³C and ¹⁵N NMR signals for coordinated and free anions. For the Ce³⁺–NCS^– system, four coordinated anion signals, displaced from the free anion signal by about +450 to +550 ppm for ¹⁵N and +50 to +80 ppm for ¹³C, are observed. The ¹³C and ¹⁵N spectral data are complementary, showing a signal area concentration dependence and measured coordination numbers consistent with the formation of Ce(NCS)²⁺ through Ce(NCS)^1- ₄. In water–methanol, the extent of complexing is decreased, presumably because of the higher dielectric constant of this medium. In addition, the results of a competitive study of NCS^– and Cl^– ion binding, carried out using ³⁵Cl NMR, is presented.     

Ag(PPh3)nX(n=1,2,3；X=Cl,Br,I)的电化学合成

银配合物;;三苯基膦;电合成;Ag(PPh3)nX(n=1;2;3；X=Cl;Br;I)的电化学合成     

NMR study (1H, 13C and 31P) of the {(C2H5)2N}nPX3−n compounds (X = Cl,C2H5; n = 0, 1, 2, 3)

¹H, ¹³C and ³¹P NMR data of the compounds {(C₂H₅)₂N}_nPX_3−n, (X = Cl, C₂H₅; n = 0, 1, 2, 3) are reported. While the ¹H and ¹³C resonances from the PEt moiety rather follow the electron-withdrawing effect of the NEt₂ substituent, ¹H and ¹³C chemical shift data from the NEt₂ moiety reveal a quite important shift contribution originating from sterically induced polarization of the CH bonds . ³¹P chemical shift data are interpreted in terms of inductive effects but the anomalous diamagnetic shift deviation from linearity for X = Cl suggests a minor contribution from

multiple bonding. The general trend observed in the ³¹P-couplings is quite straightforward and can be qualitatively explained by Bent's rule.     

Synthesis and Characterization of Silver(I) Complexes with C-Alkyl Functionalized N,N′-Diphenylamidinates: Tetrameric and Trimeric Structural Motifs

N,N–Diphenylamidines and the silver(I) complexes of their deprotonated anions have been synthesized. Previously uncharacterized tetrameric structural motifs were produced by the inclusion of alkyl substituents at the amidinate carbon. The addition of a 2-methoxy functional group to the phenyl ring resulted in a cationic silver trimer in which hydrogen bonding links silver(I)-bound water molecules to the methoxy substituents. The thermal stabilities of the tetrameric species vary with alkyl chain length. The new complexes are: tetrakis(N,N-diphenylpropamidinato) tetra silver(I), 1, tetrakis(N,N-diphenylbutamidinato) tetrasilver(I) 2, tetrakis(N,N-diphenylpentamidinato) tetra silver(I) 3, (N,N-diphenyloctamidinato)silver(I) 4, (tetrakis(N,N-di(4-n-butyl)phenylpropamidinato)tetrasilver(I), 5, bis(N,N-di(2-methoxy)phenylacetamidinato)diaquatrisilver(I) nitrate 6 and tetrakis(N,N-di(4-methoxy)phenylacetamidinato) tetrasilver(I), 7. Compounds 1, 5, 6 and 7 were structurally characterized by X-ray methods.     

Computational design and structure-property relationship studies on (I2GaN3) n (n = 1–4) clusters

To look for the single-source precursors, density functional theory calculations were performed to study structures, IR spectra, and stabilities of the possible isomers for the clusters (I₂GaN₃) _n (n = 1–4). It is found that the optimized (I₂GaN₃) _n (n = 2–4) clusters all possess cyclic structure containing Ga-N_α-Ga linkages, and azido group in azides has linear structure. Trends in geometrical parameters with the oligomerization degree n are discussed. The IR spectra are obtained and assigned by vibrational analysis. Thermodynamic properties are linearly correlated with the oligomerization degree n as well as the temperature. Mean-while, the oligomerizations can occur spontaneously at 298.2 K.     

Synthesis,Crystal Structure and Theoretical Calculations of a Nickel(Ⅱ) Coordination Polymer Assembled by 4,4'-Oxydibenzoic Acid and 1,3-Bis(imidazol-1-ylmethyl)-benzene Ligands

A new metal-organic coordination polymer [Ni(oba)(mbix)(H2O)]n·n H2O(H2oba = 4,4‘-oxydibenzoic acid,mbix = 1,3-bis(imidazol-1-ylmethyl)-benzene) 1 has been hydrothermally synthesized and structurally characterized by elemental analysis,IR,TG,UV and single-crystal X-ray diffraction.Green crystals crystallize in the triclinic system,space group P1 with a = 10.1915(18),b = 11.415(2),c = 12.314(2)?,α = 74.263(3),β = 84.545(2),γ = 74.369(3)o,V = 1327.6(4) ?,C28H26N4 Ni O7,Mr = 589.24,Dc = 1.474 g/cm3,F(000) = 612,Z = 2,μ(Mo Kα) = 0.786 mm-1,the final R = 0.0332 and w R = 0.0869 for 4622 observed reflections(I 2σ(I)).The structure of 1 exhibits a one-dimensional chain-like structure.In addition,natural bond orbital(NBO) analysis was performed by the PBE0/LANL2 DZ method in Gaussian 03 Program.The calculation results show obvious covalent interaction between the coordinated atoms and Ni(Ⅱ) ion.     

Two New Zn(Ⅱ) and Co(Ⅱ) Coordination Polymers Constructed by 4-Bromobenzoic Acid and 1,4-Bis(imidazol-1-yl)-butane: Synthesis,Crystal Structure and Theoretical Calculations

Two new coordination polymers, [Zn(bba)_2(bib)]_(2n)(1) and [Co_(0.5)(bba)(bib)_(0.5)]_(2n)(2)(Hbba = 4-bromobenzoic acid, bib = 1,4-bis(imidazol-1-yl)-butane), have been hydrothermally designed and synthesized, and their structures were determined by elemental analyses, IR spectroscopy, TG, fluorescence spectroscopy, X-ray single-crystal and powder diffraction. Complexes 1 and 2 both belong to the monoclinic system and exhibit one-dimensional zigzag chain-like structure. In addition, we analyzed Natural Bond Orbital(NBO) in using the PBE0/LANL2 DZ method built in Gaussian 03 Program. The calculation results indicated the obvious covalent interaction between the coordinated atoms and Zn(Ⅱ), Co(Ⅱ) ions.     

Synthesis, Characterization and DFT Calculation of a New Silver(Ⅰ) Iodide Templated by Conjugated Cation: (ipq)4Ag4I8

A silver iodide, (ipq)4Ag4I8 1, has been synthesized in the presence of ipq (ipq =N-(isopentyl)-quinolinium) acting as a structure-directing reagent (SDA). Compound 1 crystallizes in the triclinic system, space group Pī, with a = 9.850(2), b = 11.564(2), c = 16.111(3) (A), α =104.64(3), β = 105.73(3), γ = 94.37(3)°, V= 1688.3(7) (A)3, Z = 2, Dc= 2.205 g/cm3, F(000) = 1042,C28H33Ag2I4N2, Mr= 1120.90,μ(MoKα) = 4.836 mm-1, the final R = 0.0363 and wR = 0.0761 for 5465 observed reflections with I ＞ 2σ(Ⅰ). 1 consists of uncoordinated structure-directing molecule and inorganic moiety tuned by organic SDA. Tetrameric Ag4I84- anion in 1 is composed of edgesharing AgI4 tetrahedra and AgI3 planar triangles. Electrostatic interaction between organic counter cations and inorganic moieties is present and contributes to the crystal packing. 1 was further characterized with IR, UV-Vis, elemental analysis and cyclic voltammetry. Based on the crystal structure data, quantum chemical calculation with DFT method was used to reveal the electronic structure and optical property of 1.     

Synthesis and Crystal Structure of a New Silver(I) Isonicotinate Coordination Polymer:[(Ag_3L_2)(ClO_4)]_n(HL=Isonicotinic Acid)

1 INTRODUCTION Solid-state supramolecular chemistry and materialscience have shown quite spectacular advances overthe last two decades. At present, supramolecular che-mistry is one of the most prosperous fields in thewhole of chemistry due to their intriguing structuraldiversity and potential application as functional ma-terials, such as metallic conductivity[1], superconduc-tivity[2], non-linear optical behavior[3] and molecularmagnetism[4] invoked from the accumulation of com-posite or…     

NMR studies on [VS4–Cun] (n=3, 4, 5, 6) clusters

The complexes containing [VS₄–Cu_n] (n=3, 4, 5, 6) clusters were characterized by NMR spectra. The relationship between the ⁵¹V NMR chemical shift and the number of copper atoms in a cluster was established. ⁵¹V NMR chemical shifts were used to identify possible products of the reactions of Cu(PPh₃)Cl and [VS₄–Cu₃] with various mole ratios in CDCl₃ in order to study their reaction mechanism in solution. The results demonstrate that the reaction of tetranuclear [VS₄–Cu₃] and Cu(PPh₃)Cl in CDCl₃ successively yields penta-, hexa- and hepta-nuclear V–Cu–S heterometallic clusters when the mole ratio of [VS₄–Cu₃] to Cu(PPh₃)Cl is decreased, and the process can be reversed when [VS₄–Cu₃] is added to [VS₄–Cu₆] gradually. Theoretical calculations were also carried out to explain the experimental results.     

Molecular Structure,Electronic Properties,Homo–Lumo,MEP and NBO Analysis of (N-Isocyanimino) Triphenylphosphorane (Ph3PNNC): DFT Calculations

Journal of Structural Chemistry - N-isocyaniminotriphenylphosphorane (Ph3PNNC) is a type of iminophosphorane which is an important reagent in synthetic organic chemistry and a ligand in metallic...     

19F,31P,1H NMR and X-ray crystallographic studies of (pentafluorophenyl)3−n (4-pyrazol-1-yl-2,3,5,6-tetrafluorophenyl) n=1,2,3 Phosphines

New phosphines1–3 have been synthetized by reaction of pyrazolate anion with tris(pentafluorophenyl)phosphine and characterized by¹H,³¹P, and¹⁹F NMR studies.¹⁹F NMR spectral data contribute to the evidence for apara-substitution of tetrafluorophenyl rings. The crystal structure of tris(4-pyrazol-1-yl-2,3,5,6-tetrafluorophenyl)phosphine 1 has been determined, proving that the assignment based on spectroscopic data was correct: C₂₇H₉F₁₂N₆P,M _r = 676.37, monoclinic, space group P2_l/c,a=10.754(2) å,b=10.316(2) å,c = 23.598(5) å,=95.36(3),V=2607(1), å³,Z=4,R ₁=0.042, andwR ₂=0.122.     

Direct Trifluoromethylthiolation of Unactivated C(sp3)?H Using Silver(I) Trifluoromethanethiolate and Potassium Persulfate

A practical and efficient method for the direct trifluoromethylthiolation of unactivated C(sp³) H bonds by AgSCF₃/K₂S₂O₈ under mild conditions is described. The reaction has a good functional‐group tolerance and good selectivity. Initial mechanistic investigations indicate that the reaction may involve a radical process in which K₂S₂O₈ plays key roles in both the activation of the C(sp³) H bond and the oxidation of AgSCF₃.     

Synthesis,Characterization and DFT Calculation of a New Silver(I) Iodid Templated by Conjugated Cation:(ipq)_4Ag_4I_8

1 INTRODUCTION The construction and characterizations of low dimensional inorganic/organic hybrid materials have increasingly attracted the interest of chemists duo to their unusual topologies and relevance in a wide range of applications in materials science including transport, magnetic materials, catalysts, and lumi- nescent materials[1]. Among the various families of hybrid functional materials, the family of metal halides is an important one. As a branch of the metal halides, silver(…     

Vibrational spectra and electronic structure of 1-germatranol, 1,1-quasi-germatrandiole,and 1,1,1-hypogermatrantriole (HO)4−n Ge(OCH2CH2) n NR3−n (R = H,Me; n = 1–3)

IR spectra of 1-germatranol, 1,1-quasi-germatrandiole, 1,1,1-hypogermatrantriole with a general formula (HO)_4?n Ge(OCH₂CH₂) _n NR_3?n (n = 1–3) are obtained. At the B3LYP/aug-cc-pVDZ density functional level the equilibrium structures and vibrational spectra of these compounds along with their hydrogen-bonded dimers are calculated. Based on the calculations the band assignment is performed in the IR spectra of 1-germatranol, 1,1-quasi-germatrandiole, and 1,1,1-hypogermatrantriole. The existence of dimers is manifested in the IR spectra as the absence of bands in the frequency ranges characteristic of the bending vibrations of Ge-OH groups and the presence of bands in the vibrational range of hydrogen-bonded germatranyl groups.     

Studies on the Stability of On-top Al13Inm (n = 1～12,m =-1,0,+1) Clusters

Energetic and electronic structures of the on-top Al13Inm (n = 1 ～12,m = -1,0,+1)clusters have been investigated by employing a first-principles pseudo-potential plane wave method.Several parameters such as binding energies,second differences of energy and vertical-electron detachment energies have been adopted to characterize and evaluate the structure stability of Al13In (n = 1 ～ 12) clusters.The optimized models show that the Al13 moieties in the clusters can not retain the original regular icosahedron structure.Results from binding energy and second difference of energy show that Al13In and Al13In- clusters with even n are more stable than those with odd n in contrast with Al13In+ clusters.The calculation of vertical-electron detachment energies (VDE) of Al13In clusters indicates that Al13In and Al13In- clusters with even n are closer to the closed shell of the Jellium model.Further analysis of electron density of states and electron density differences reveals that the enhanced stability of Al13In- clusters is not only associated with the closed shell of valence electrons but also with the bonding type between I and associated Al atoms.     

Vibrational spectra,force fields and NMR-data for triorganyl-tetrelomethanes CH4−n(TtR3)n (Tt = Sn and Pb)

Based on vibrational spectra normal coordinate calculations have been carried out for trimethyltetrelomethanes CH_4−n(TtMe₃)_n (Tt = Sn and Pb, n = 2 and 4). The resulting comparable force constants of the two distinguishable types of carbon-metal bonds for Tt = Sn (range K(C-Sn) 220 - 180 Nm⁻¹) are 10 – 15% higher than for Tt = Pb (K(C-Pb) 190 - 170 Nm⁻¹). These force constants K(C-Tt) are similar to the K(C-Hg) values of corresponding methylmercuriomethanes CH_4−n(HgMe)_n. The force constants K (C-Tt), and also the coupling constants ¹J(Tt,C) from NMR spectra, indicate weakening of the carbon-metal bonds in the central CTt_n groups with growing n, whereas the peripheral TtMe bonds are almost unaffected by variations of n.     

Silver(I) complex with 2-amino-4,4α-dihydro-4α,7-dimethyl-3H-phenoxazin-3-one (Phx-1) ligand: crystal structure,vibrational spectra and biological studies

The first metal complex of Phx-1 ligand, bis(2-amino-4,4α-dihydro-4α,7-dimethyl-3H-phenoxazin-3-one)nitratosilver(I), [Ag(Phx-1)₂NO₃], has been obtained and investigated by single crystal X-ray diffraction and vibrational spectroscopy methods. The Ag⁺ is bonded to heterocyclic nitrogen atoms of two organic ligands and one oxygen atom of a nitrate anion. The Phx-1 ligand coordination mode is supported by IR and Raman spectra, interpreted with the help of theoretical DFT studies. The antibacterial activity of the ligand and its Ag(I) complex as well as some reference compounds were screened against Gram-positive and Gram-negative bacteria, applying microdilution procedures. High sensitivity to the studied complex was found for Rhodococcus erythropolis and Bacillus licheniformis strains. Modified Phx-1 ligand preparation procedures are also presented.     

Tricarbonylrhenium(I) bromide complexes with N,N′-bis[1-(4-chlorophenyl)ethylidene]ethane-1,2-diamine and N,N′-bis[1-(4-nitrophenyl)ethylidene]ethane-1,2-diamine–syntheses,structures, electrochemical and spectroscopic studies

Two rhenium(I) complexes, [Re(CO)₃Br(L ⁿ )] (n = 1, 2), (L¹= N,N′-bis[1-(4-chlorophenyl)ethylidene]ethane-1,2-diamine and L² = N,N′-bis[1-(4-nitrophenyl)ethylidene]ethane-1,2-diamine) have been synthesized and characterized by CHN analyses, ¹H NMR, IR, and UV-Vis spectroscopy. The molecular structure of [Re(CO)₃Br(L¹)] is a distorted octahedron around rhenium with one Br, facial arrangement of three CO's, and one diimine. The UV-Vis spectra of the complexes have metal-to-ligand charge transfer bands increasing in wavelength when the L² ligand is replaced by L¹, in agreement with the oxidation potential of the complexes.