THE CRYSTAL STRUCTURES OF 10,10′-BIS(PHENOXARSINE) OXIDE AND SELENIDE

Abstract

The reaction between 10,10′-bis(phenoxarsine) oxide (I) and HI gives 10-iodophenoxarsine. The latter, on treatment with H₂Se give 10,10′-bis(phenoxarsine) selenide (II). The crystal structures of I and II have been determined from single crystal X-ray data. The unit cell for I is monoclinic, P2₁/c (No. 14) with a = 15.976(3) Å, b = 10.582(2) Å, c = 12.581(2) Å, β = 111.70(1)° V = 2018.6 ų; d(calc.) = 1.65Mg/m³ at 23°C for four molecules per unit cell. From 3279 reflections for which I>0.5σ(I), F>σ(F), R = 0.041 with anisotropic thermal parameters for all non-hydrogen atoms and with fixed positions and thermal parameters for hydrogens. One of the phenoxarsina rings deviates from planarity by approximately 5° while the other deviates by more than 24°. The (As[sbnd]O) distances are 1.810(3) and 1.821(3) Å for the flat and bent ring and the (As[sbnd]O[sbnd]As) angle is 122.3(1)°. The bond distances to As and O from C are nearly the same for both rings, but the bond angles with As and the ring O as the apex are systematically larger for the flat ring. For II the unit cell is triclinic, P1 (No. 2) with a = 9.368(1) Å, b = 14.089 Å, c = 9.269(2) Å, α = 111.37(2), β = 113.11(2), γ = 74.76(1); V = 1037.5 ų, d(calc) = 1.81 Mg/m³ for two molecules per unit cell at 23°C. From 2945 reflections for which I > 0.5σ(I), F > σ(F), R = 0.055 with anisotropic thermal parameters for all non-hydrogen atoms and with fixed positions and thermal parameters for hydrogen. One of the phenoxarsina rings deviates by 3° from planarity and the other by 8°. The (As[sbnd]Se) bond distances are 2.416(1) and 2.406(1) Å. The (As[sbnd]Se[sbnd]As) bond angle is 96.66(4)° and the corresponding (As[sbnd]C) and (C[sbnd]C) distances in the two rings are nearly the same. In comparison with I, the angles with As or O as the central atoms are about the same in both rings of II.     

Monocyclic and Fused 4-Imino(4-Oxo)-1,3,2-Diazaphospholanes and - Phosphorinanes. Synthesis and Some Properties

Abstract

In contrast to the great variety of well known phosphorus heterocycles with exocyclic C=O double bond the number of ones containing exocyclic C=N bond is unusually modest. We elaborated the convenient method of preparation of various N,P,N-heterocycles with exocyclic C=N bond (1–4) from the readily available corresponding amino acid amidines and appropriated dichlorides or diamides of phosphorus (III) acids. Rings' 1–3 with P(III) are easily converted into (thio)phosphoryl derivatives, while the direct phosphorylation of amino amidines by RP(Y)Cl₂ is unusually ineffective. Tricycles 4 - derivatives of 2-(2-amino pheny1)imidazoline - mainly exist in the more conjugated hydrophosphazo tautomeric form 4b (>90 %).     

ELEMENTAL SULFUR REACTIONS WITH 2-PICOLINE

Abstract

A study of the reaction of the elemental sulfur with 2-picoline is reported. The process was carried out at the boiling point of the 2-picoline under argon. After removing unreacted solids, the reaction products were identified by means of LC. GC and GC-MS. The following products have been identified by mass spectrometry: 1,2-di/2-pyridyl/-ethane. 1,2-di/2-pyridyl/-ethene. 2-methyl-x-[/2-pyridyl/methyl]pyridines, 2-mercapto-methyl-[x/2-pyridyl/methyl]-pyridines, l-mercapto-1,2-di/2-pyridyl/-ethane, 5,6-di/2-pyridyl/-5H-cyclopenta-[b]pyridine, 5,6-di/2-pyridyl/-7H-cyclopenta[b]pyridine, 1,2,3-tri/2-pyridyl/-propane. 1,2-di/2-pyridyl/-1-[x-/2-methyl/-pyridyl]-ethane, 5,6-di/2-pyridyl/-7-[/2-pyridyl/methyl]-7H-cyclopenta[b]pyridine, 5,6-di/2-pyridyl/-5-[/2-pyridyl/-methyl]-5H-cyclopenta-[b]pyridine. Di{7-[5,6-di/2-pyridyl/-7H-cyclopenta[b]pyridyl]} sulfide and di(7-[5,6-di/2-pyridyl/-7H-cyclopentalblpyridyl]} disulfide.     

Synthesis and Polymerization of the Organometallic Monomer Series Based on Cymantrenylethyl Acrylate

{η⁵ -C₅H₄[CH(CH₃)OC(O)CH = CH₂])Mn(CO)3, {η⁵—C₅[CH-(CH₃)OC(O)C(CH₃)=CH₂]]Mn(CO)₃, and {η⁵—C₅H₄[CH(CH₃)-OC(O)CH=C(CH₃)2])Mn(CO)₃ were synthesized (63, 57, and 51%, respectively) from {η⁵—C₅H₄[CH(CH₃)OH])Mn(CO)₃, toluene-sulfonic acid, and the acrylic, methacrylic, and dimethylacrylic acids, and from (η⁵-C₅H₄[CH(CH₃)OH]}Mn(CO)₃, pyridine, and the acrylic, methacrylic, and dimethylacrylic acyl chlorides [26, 48, and 25% (impure), respectively]. No product was obtained when NaH was used as the base in the latter method. The acrylate and methacrylate monomers were bulk homopolymerized at 65°C with AIBN (75% yield, M_n = 88,550 g/mol; 78% yield, M_n = 349,350 g/mol, respectively). The dimethylacrylate did not polymerize under these conditions. The polymers lost vinylcymantrene upon heating to 257 and 279°C, respectively. The polymers did not exhibit a clear T_g but were observed to soften at 85 and 160°C, respectively, and they could be pulled into fibers.     

A Review of the Status of Polymerization in Thermotropic Liquid Crystal Media and Liquid Crystalline Monomers

Thermotropic liquid crystals offer uniquely ordered media for intermolecular reactions such as polymerization. Unlike the recently investigated topochemical polymerizations where molecules are rigidly constrained on lattice points [l], the liquid crystalline state permits full two-dimensional (nematic and cholesteric) and one-dimensional (smectic) movement. In addition, various degrees of translational freedom are attainable depending on the class of mesogen. Such freedom of choice, plus the ability to orient nematic and cholesteric mesogens on a molecular scale in an electric or magnetic field or on certain surfaces, makes the liquid crystal state an attractive polymerization medium.