"Phosphorus, Sulfur, and Silicon and the Related Elements"

Rudd, Martin D.; Defferding, Angela; Klausmeyer, Kevin K.

doi: 10.1080/10426500802202063pmid: N/A

The reaction of naphthyl tellurium trihalides, ArTeX3 (X = Br, Cl; Ar = naphthyl) with several salts of dithiocarbamate and xanthate ligands (L) have been investigated by metathesis in tetrahydrofuran. The products (1–3) were characterized by multinuclear NMR spectroscopy and elemental analysis. Crystals of ArTeL (L = 1-pyrrolidine-carbodithioate, 1) were obtained from the reaction of ArTeCl3 and 3 equivalents of NH4[S2CNC4H8]. The structure shows a three-coordinate T-shaped tellurium(II) geometry with one “short” and one “long” Te-S bond: the two independent molecules in the unit cell have Te-S distances of 2.444(3) Å, 2.494(3) Å and 3.271(5) Å, 3.042(5) Å respectively, the latter two distances being intermolecular. The intermolecular interactions and the NMR spectra are discussed, together with a structural comparison of related Te(II) complexes.

Alaghaz, Abdel-Nasser M. A.

doi: 10.1080/10426500801963624pmid: N/A

1,3-diphenyl-2,2,4,4-tetrachloro-2,4-bis(4-Cyano-5,6-dimethyl-py-ridazin-3(2H)-one) cyclodiphosph(V)azane(III), reacts with stoichiometric amounts of transition metal salts such as Mn(II), Fe(III), Fe(II), Co(II), Ni(II), Cu(II), Zn(II), Cd(II) and UO2(II) to afford colored complexes in a moderate to high yield. The complexes have been investigated in solution by the spectrophotometric molar ratio and conductometeric methods. The formula of the isolated complexes was suggested based on elemental analyses, IR, molar conductance, UV-Vis, 1H NMR, mass spectra, solid reflectance, and magnetic susceptibility measurements. From the elemental analyses data, 1: 2 (III : M) ratio is suggested and the complexes are found to have the general formula [(MXn)2(III)(H2O)m].yX where M = Mn(II) (X = OCOCH 3 , n = 2, m = 4, y = 0), Fe(III) (X = Cl, n = 2, m = 2, y = 2), Fe(II) (X = SO4, n = 1, m = 2, y = 0), Co(II) (X = OCOCH3, n = 2, m = 4, y = 0), Ni(II) (X = OCOCH3, n = 2, m = 4, y = 0), Cu(II) (X = OCOCH3, n = 2, m = 4, y = 0), Zn(II) (X = OCOCH3, n = 2, m = 4, y = 0), Cd(II) (X = Cl, n = 2, m = 4, y = 0), and UO2(II) (X = NO3, n = 1, m = 0, y = 2). The IR and 1H NMR spectral data revealed that III behaves as a neutral bidentate ligand coordinated to the metal ions through oxygen (O) and nitrogen N atoms. The UV-Vis, solid reflectance, and magnetic-moment data have shown that the ligands are coordinated to the metal ions in an octahedral manner. The molar conductance data show that the complexes are nonelectrolytes while the Fe(III) and UO2(II) complexes are 1:2 electrolytes. The in vitro–biological activity of some newly synthesized compounds against gram-positive and gram-negative bacteria was studied.

Patel, H. S.; Patel, K. B.

doi: 10.1080/10426500801963772pmid: N/A

4-Amino-1,2,4-triazole (1) undergoes facile condensation with aromatic aldehydes to afford the corresponding 4-(arylidene-amino)-4H-[1,2,4]-triazole (2 a−h) in good yields. Cyclocondensation of compounds (2 a−h) with thioglycolic acid yields 3-[4H-(1,2,4)-triazolyl]-2-aryl-1,3-thiazolidin-4-ones (3 a−h). The structures of these compounds were established on the basis of analytical and spectral data. The newly synthesized compounds were evaluated for their antibacterial and antifungal activities.

Nori-Shargh, Davood; Rafatpanah, Shamsi

doi: 10.1080/10426500801963780pmid: N/A

NBO analysis, density functional theory (DFT: B3LYP/6-31G*//B3LYP/6-31G*) and ab initio molecular orbital (MO: MP2/6-31G*//B3LYP/6-31G*) based methods were used to study the stereoeletronic effects on the conformational properties of 1,3-dioxane (1), 1,3-dithiane (2) and 1,3-diselenane (3). The obtained B3LYP/6-31G*//B3LYP/6-31G* and MP2/6-31G*//B3LYP/6-31G* results show that the ring flipping barrier heights [via rotation about C─M bond, (M ═ O (1), M ═ S (2) and M ═ Se (3))] decrease from compound 1 to compound 3. Based on the optimized ground state geometries using B3LYP/6-31G** method, the NBO analysis of donor-acceptor (bond-antibond) interactions revealed that the stabilization energies associated with the electronic delocalization from the equatorial non-bonding Lone Pair orbitals [LP(e)M1] to σ C2− M3 antibonding orbitals, decrease form 1 to 3. The LP(e)M1→ σ C2− M3 resonance energies for compounds 1–3 are 12.66, 6.73 and 5.33 kcal mol−1, respectively. The LP(e)M1→ σ C2− M3 delocalizations could fairly explain the decrease of occupancies of LP(e)M1 non-bonding orbitals and the increase of occupancies of σ C2− M3 anti-bonding orbitals, from compound 1 to 3. The electronic delocalization from LP(e)M1 non-bonding orbitals to σ C2− M3 anti-bonding orbitals increase the ground state structure stability, therefore, the decrease of LP(e)M1→ σ C2− M3 delocalizations could fairly explain the easiness of ring flipping processes from compound 1 to 3.

Nori-Shargh, Davood; Hosseini, Maryam Malek; Ohaninan, Tina

doi: 10.1080/10426500801963798pmid: N/A

An investigation employing the ab initio molecular orbital (MO) and density functional theory (DFT) methods to calculate structural optimization and conformational interconversion pathways for the two diastereoisomeric forms, (±) and meso configurations of 1,3,7,9-tetraphospha-cyclododeca-1,2,7,8-tetraene (1) was undertaken. Two axial symmetrical conformations are found for (±)-1 configuration. (±)-1-TB axial symmetrical form is found to be about 0.35 and 0.99 kcal mol−1 more stable than (±)-1-Crown axial symmetrical conformation, as calculated by HF/6-31G*//HF/6-31G* and B3LYP/6-31G*//HF/6-31G* levels of theory, respectively. The unsymmetrical meso-1-TBCC form is found to be the most stable geometry, among the various conformations of meso-1 configuration. HF/6-31G*//HF/6-31G* and B3LYP/6-31G*//HF/6-31G* results showed that between the two most stable conformations of (±) and meso configurations, (±)-1-TB is more stable than meso-1-TBCC by about 3.35 and 2.43 kcal mol−1, respectively. In addition, MP2/6-31G* and B3LYP/6-311+G** results showed that the (±)-1-TB form is about 1.10 and 2.36 kcal mol−1 more stable than the meso-1-TBCC form. Further, NBO results revealed that in the most stable form of meso configuration (meso-1-TBCC), the sum of the π* allenic antibonding orbital occupancies (Σ π *occupancy) is greater than dl configuration ((±)-1-TB). Also, NBO results indicated that in the (±)-1-TB conformer, the sum of σ and π allenic moieties bonding orbital deviations (Σ σ dev+Σ π dev) from their normal values, is lower than in the meso-1-TBCC form.

Hommer, Herbert; Cuevas, Gabriel; Gordillo, Barbara

doi: 10.1080/10426500801963822pmid: N/A

By following a previously reported method,1 the synthesis of r-2-alkoxy-cis-4-cis-5-dimethyl-1,3,2-λ3-dioxaphospholanes ligands (1 and 3) was carried out. The purpose of this work is the kinetic study of the inversion barrier at phosphorus for 1 and 3 and the comparison with the already informed dioxaphospholane 2. The kinetic measurements of the thermal isomerization cis-to-trans were performed by 31P NMR spectroscopy, observing a first order kinetics for both compounds. The energy of activation (Ea) for the epimerization of compounds cis-1 and cis-3 was calculated to be 16.0 ± 0.6 and 11.8 ± 0.8 kcal/mol, respectively. The values of the thermodynamic parameters of the transition state (Δ H≠, Δ S≠, Δ G≠) suggest that the inversion at phosphorus not only depends on the spatial requirements of the alkoxy substituent but also on entropic effects. The thermodynamic parameters Δ H°, Δ S°, and Δ G° were also evaluated and they show that the cis isomers are preferred from enthalpic point of view, but entropic effects dominate the equilibrium trans ⇌ cis leading to the entropically favored trans isomers. Furthermore, the results are supported by density functional theory calculations of 1–4 at the B3LYP/6-31G** level.

Nami, Navabeh; Hosseinzadeh, Masoumeh; Rahimi, Ehteram

doi: 10.1080/10426500801963855pmid: N/A

The reaction of 4-oxo-2-(2-oxo-1,2-dihydroindol-3-ylidene)hydrazone-1,3-thiazin-6-methyl carboxylate 2 with hydrazine hydrate in methanol gave 4-oxo-2-(2-oxo-1,2-dihydroindol-3-ylidene)hydrazone-1,3-thiazin-6-carbonylhydrazine 3. Furthermore, the reaction of 3 with carbon disulfide and then hydrazine hydrate afforded 3-[6-(4-amino-5-thioxo-4,5-dihydro-1H-1,2,4-triazol-3-yl)-4-oxo-1,3-thiazin-2-yl] hydrazone-1,3-dihydroindol-2-one 5. the latest reacted with DMAD to give {6-hydroxy-3-[4-oxo-2-(2-oxo-1,2-dihydroindol-3-ylidene)hydrazone-1,3-thiazin-6yl]-[1,2,4]triazolo[3,4-b][1,3,4]thiadiazin-7-ylidene}methoxycarbonylmethylene 6.

Abdel-Fattah, Azza M.; Shaif, Labeeb M.; Attaby, Fawzy A.

doi: 10.1080/10426500801963905pmid: N/A

The present study aimed to investigate the synthetic potentiality and chemical reactivity of 2-thioxo-1,2-dihydropyridine-3-carbonitrile derivative 1. This goal performed via its reaction with each of 1-chloroacetone and iodomethane to afford the corresponding 2-alkylthio derivatives 3 and 9, respectively. Compound 3 underwent intramolecular cyclization to afford the corresponding thieno[2,3-b]pyridine derivative 4 which in turn, reacted with dimethylformamide/dimethylacetal followed by hydrazine hydrate and nitrous acid to afford the corresponding pyridothienopyrimidine and pyridothienopyridazine derivatives 6 and 8, respectively. On the other hand, Compound 9 reacted with hydrazine hydrate to give 3-aminopyrazolo[3,4-b]pyridine derivative 10, which diazotized with nitrous acid to give the corresponding diazonium salt 11. Compound 11 coupled with several active –CH2-containing reagents to synthesize the corresponding pyridopyrazolo-triazines 15, 24, 29, and 31. The formulas of all newly synthesized heterocyclic compounds were elucidated by considering the data of IR, 1H NMR, Mass spectral data, as well as data from elemental analyses.

Soni, Kusum; Jhajharia, Priyanka; Mittal, Sarita; Seth, Gita

doi: 10.1080/10426500801964002pmid: N/A

The inhibitory effects of a recently introduced series of N-phosphorylated/ thiophosphorylated compounds on Aspergillus niger and Fusarium oxysporium were examined. The derivatives were obtained in good yield by reacting 2-(2′-aminophenyl)benzoxazole with phosphorous oxychloride and thiophosphoryl chloride in different molar ratios (1:1, 2:1, and 3:1). Structure elucidation of all synthesized compounds was based on the data of elemental analysis, IR, 1H NMR, and 31P NMR spectra.

Alaghaz, A. M. A.; Shaaban, S. M.

doi: 10.1080/10426500801964028pmid: N/A

Correlation of the current-voltage and temperature dependence of the electrical conductivity with the molecular structure data including infrared and ultraviolet spectra of ligand [2,2,4,4-tetrachloro-1,3-diphenyl-2,4-bi(5-imino-4-cyano-3-methylthiopyazo-1-yl-methylcarbodi-thioate)cyclodiphosph(V)zane and its copper complex have been investigated. The result of the electrical conductivity, energy gaps obtained from electrical conductivity in the solid state was consistent with those of semiconductor materials.