The crystal and molecular structure of the cycloadduct from an activated carbodiimide and methyl isothiocyanate

The crystal and molecular structures of the cycloadduct from isopropyl[α-(dimethylthio-carbamoyl)isopropyl]carbodiimide and methyl isothiocyanate were determined by single-crystal X-ray methods. The product was established to be 2-(1-isopropyl-3,5-dimethyl-4,6-dithioxo-hexahydro-1,3,5-triazine-2-ylidenamino)-N,N-dimethylthioisoburyramide, in which contrary to expectations based on hybridisation the heterocyclic ring adopts a boat conformation.     

Penta- and tetracoordinated phosphorous in reactions of biacetyl with diethylacetylphosphite and diethyl chlorophosphite

Conclusions Diethylacetyl phosphite and diethyl chlorophosphite react with biacetyl, intermediately forming, as do other derivatives of phosphorous acid, 1,3,2-dioxaphospholenes with a pentacoordinated phosphorous atom; the latter are rapidly transformed to noncyclic or cyclic derivatives of tetracoordinated phosphorous.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 11, pp. 2609–2611, November, 1968.Deceased.     

Synthesis and spectroscopy of phosphonate derivatives of uracil and thymine. X-ray crystal structure of diethyl 6-uracilmethylphosphonate

A new class of phosphonate ligands, derived from uracil and thymine was designed, prepared and characterised. Dimethyl ( 4, 7 ) and diethyl ( 5, 8 ) uracilmethylphosphonates have been prepared by the reaction of chloromethyluracil isomers 2 and 3 with trimethyl phosphite and triethyl phosphite, respectively. The corresponding free acids, 5-uracilmethylphosphonic acid 6 and 6-uracilmethylphosphonic acid 9 , have also been isolated. The structure of the compounds has been assigned by nmr spectroscopy and, in the case of 8 , confirmed by X-ray analysis.     

Chemistry of Succinylsuccinic Acid Derivatives. Part II. The crystal and molecular structure of diethyl succinylsuccinate

X-ray structure analysis of the title compound (I) is reported. The results are interpreted to predict formation of anti-tricyclo[4.4.0^1,6.0^7,12]-1,4,7,10-tetraethoxycarbonyl-3,6,9,12-tetrahydroxy-dodeca-3,9-diene on UV.-irradiation of solid (I).     

NMR spectra of the cycloaddition adducts between tetracyanoethylene oxide and norbornadiene derivatives

The NMR spectra of the cycloaddition adducts between tetracyanoethylene oxide (TCNEO) and norbornadiene derivatives have been studied. It was shown that there was significant long-range coupling between 7-anti and endo hydrogens in the adducts and that this long-range coupling was solvent dependent. Based on the present study it is concluded that the long-range coupling between endo and anti hydrogens can be as high as 4·1 Hz when an electronegative substituent is attached to the carbon which bears endo hydrogen.     

Synthesis ofo-thiatelluraphenylenezirconocenes. X-ray crystal structure of

o-Thiatelluraphenylenezirconocene complexes were obtained in good yield by reaction of dilithiumo-benzenthiatelluride with zirconocene dichlorides. These compounds represent the first examples of heterodichalcogenaphenylene bent metallocences. They were characterized by spectroscopic methods and the effect on the n.m.r. results of stepwise substitution of one and two Te atoms for S is discussed. X-ray crystal structure analysis was performed for one representative complex. The structure is very similar to that previously reported for a diselenaphenylene complex, but the disorder observed for chalcogen atoms prevents an accurate comparison of the geometrical parameters with other related compounds.     

Molecular ordering and structure of quasi-spherical solutes by liquid crystal NMR and Monte Carlo simulations: the case of norbornadiene

Norbornadiene (a C2v symmetry bicyclic rigid hydrocarbon) dissolved in three different nematic mesophases has been studied by liquid crystal NMR, to contribute to a better understanding of the influence of solvents on the solute's ordering and structure. The main results achieved by this work can be summarized as follows: (i) the order parameters obtained by the analysis of the 1H NMR spectra (at different temperatures) were successfully reproduced by a recently proposed model of solute/liquid crystal interactions, by using Monte Carlo numerical simulations; (ii) the theoretical (B3LYP/6-31++G**) "equilibrium" geometry of norbornadiene, vibrationally corrected by using the force field calculated at the same level, is compatible (within, at most, a 5% error) with experimental LXNMR data. This leads to the conclusion that the structure is not significantly distorted by the tested solvents.     

Synthesis and crystal structure of diferrocenylmethoxyethylamine

The reaction of diethanolamine with diferrocenylmethyl carbonium (2) that was generated by diferrocenylmethanol (1) treated with BF₃ in CH₂Cl₂ provided the synthesis of title compound diferrocenylmethoxyethylamine (3). The structure of 3 was determined by the X-ray diffraction (XRD) with crystal data: monoclinic P2₁/n space group and a=5.8419(14) Å, b=13.572(3) Å, c=23.839(6) Å, α=90°, β=91.827(5)°, γ=90°, V=1889.2(8) Å³, Z=4, D _c =1.558 mg·m^?3, μ=1.548 mm^?1, F(000)=920. The intra- and inter-molecular H bonding modes in 3 were demonstrated both in molecular crystal structure and IR spectral characterization.     

Synthesis and crystal structure of poly-trivinyltinferrocenoate

Binuclear complexes of formula C₅H₁₅FeC₅H₄COOSn(CHCH₂)₃ (I), C₅H₅FeC₅H₄COOSnPh₃ (II) and Ph₃GeCOOSnPh₃ (III) have been prepared and characterized by IR spectra. The polymeric structure of solid C₅H₅FeC₅H₄COOSn(CHCH₂)₃ has been established by X-ray crystallography. The crystals are monoclinic, space group P2₁/a, with a 15.105(5), b 10.030(4), c 11.402(4) Å, and β 104.06(4)°. In this compound the tin atoms are five-coordinate trigonal bipiramidal, with the vinyl groups equatorial and two apical oxygen atoms from bridging carboxylato groups. The resulting structure is a linear polymer with SnO bond lengths of 2.12 and 2.42 Å. The spectra indicate that similar polymeric structure exist also for compounds II and III in the solid state, whereas an equilibrium monomer ? dimer seems to be present in CHCl₃ solution for the compound III.     

Synthesis and crystal structure of azafulgides

Two azafulgides were synthesized and their crystal structures determined by a single crystal X-ray diffraction analysis. The substances crystallized in the following symmetries and cell parameters. C₂₃H₁₉NO₃( 2 ): triclinic space group P&1bar; with a = 7.243(2). b = 10.981(6) and c = 12.672(8)Å, α = 80.40(5)°, β = 75.58(4)° and γ = 77.32(3)° Z = 2; C₁₉H₁₉NO₃( 1 ): orthogonal space group C_2v⁹-Pmc2₁ with a = 8.079(8), b = 12.752(9) and c = 15.752(13)Å, Z=4. The calculated densities are 1.26 and 1.27 g/cm³ respectively for 2 and 1 . The crystal structures were determined by direct methods. The least-squares refinement led to R values of 0.044 and 0.058 for 2 and 1 for 2738 and 952 reflections with I > 3σ-(I) respectively.     

Pauson–Khand cycloaddition reactions of chiral ynamides. Observation of an unusual endo-addition with norbornadiene

Pauson–Khand cycloadditions using chiral ynamides are achieved in modest to good yields with excellent regioselectivity and modest stereoselectivity. An unusual endo addition is found when using norbornadiene and substituted ynamides, leading to cycloadducts that were not observed in previous studies using ynamides or ynamines.     

Synthesis and crystal structure of 2,6-bis(N-cytisinomethyl)-4-phenyl-1,4-dihydropyridine-3,5-dicarboxylic acid diethyl ester

By the interaction of the diethyl ester of 2,6-bis(bromomethyl)-4-phenyl-1,4-dihydropyridine-3,5-dicarboxylic acid with two moles of the alkaloid cytosine, the corresponding 2,6-bis(cytisinomethyl) derivative was obtained. The spatial structure of the product was demonstrated by ¹H NMR spectroscopy and X-ray structural analysis.     

The electronic structure of transition-metal carbonyl complexes of norbornadiene and mesitylene

The photoelectron spectra of several transition-metal carbonyl complexes of norbornadiene and mesitylene have been measured. The data for the norbordiene complexes have been compared with those reported previously for norbornadieneiron tricarbonyl. The shifts in energies of the π orbitals of the ligands introduced by the metal carbonyl moieties are remarkably insensitive to the choice o0f transition metal or geometry of the complex. However, the characters of the metal d-orbital ionization bands are markedly affected by the choice of ligand.     

三乙四胺六乙酸钆配合物的合成及晶体结构

在水溶液中合成了三乙四胺六乙酸钆配合物:K4[Gd2(HTTHA)2].14H2O的单晶, 并测定了其结构。晶体属单斜晶系, P21/n空间群。晶胞参数: a=1.1266(5)nm,b=2.5686(4)nm, c=2.2076(8)nm, β=102.50(3)°,V=6.237(6)nm^3, Z=4, Dc=1.812g/cm^3。配合物是比核分子,每个钆离子与来自同一个三乙四胺六乙酸的3个氮原子和4个羧基氧原子, 来自另一个三乙四胺六乙酸的2个羧基氧原子配位,形成三冠三角棱柱型配位多面体。     

Synthesis and crystal structure of a Pb complex with ciprofloxacin

A hydrothermal reaction of ciprofloxacin with PbCl₂ · 2H₂O and Na₂S yields a metal complex [Pb₂(H-Cip)₆S]Cl₆ (I), which was characterized by elemental analysis, IR, and single crystal diffraction analyses. Complex I crystallizes in the rhombohedral system, space group $R\bar 3c$ , with lattice parameters a = 15.7800(7), c = 77.901(9) ?, V = 16799(2) ?³, Z = 12, ??_calcd = 1.646 mg/m³.