Herman P. Perzanowski

Polymerization of functionalized diallyl quaternary ammonium salt to poly(ampholyte–electrolyte)

Abstract The quaternary ammonium salt, N,N-diallyl-N-carboethoxymethyl-N-carbomethoxypentylammonium chloride 13, on polymerization in aqueous solution using tert-butylhydroperoxide, afforded the polyelectrolyte 14. The copolymer 15 of the monomer 13 and sulfur dioxide was synthesized in excellent yield. The polyelectrolytes 14 and 15 on acidic hydrolysis gave the poly(ampholyte–electrolytes) 16 and 17 which contain structural features common to both polyampholytes and conventional polyelectrolytes. The solution properties of these polymers are discussed in detail. The poly(ampholyte–electrolyte)s, 16 and 17 are shown to have considerably higher viscosity than their corresponding polyelectrolytes 14 and 15.

Silver(I) complexes of thiourea

AgI complexes of thiourea (tu) having the general formula Ag(tu)xNO3 (x = 1–4) have been prepared and characterized by elemental analyses, i.r. and n.m.r. (1H, 13C, 15N and 107Ag) spectroscopy. Separate i.r. bands were observed for terminal and bridging tu ligands in the complexes. The Ag(tu)NO3 complex is assumed to be polymeric with all tu groups in the bridging mode. A consistent upfield shift in the 13C-n.m.r. chemical shift is observed as the number of tu groups attached to AgI increases, whereas the opposite trend is observed for 1H, 15N and 107Ag chemical shifts.

The 1,3-dipolar cycloaddition of cyclic nitrones with 1,2-disubstituted alkenes

Abstract A comparative study of the stereochemical behaviour of the 1,3-dipolar cycloaddition of a series of 1,2-disubstituted alkenes with 1-pyrroline 1-oxide ( 1 ) and 2,3,4,5-tetrahydropyridine 1-oxide ( 2 ) has been carried out. Both the nitrones exhibit very similar stereochemical properties. Rate constants for the cycloaddition of these nitrones to several disubstituted alkenes have been determinded at 36°C by 1 H n.m.r. spectroscopy. It is found that the nitrone 1 reacts slower than 2 due to the presence of bond eclipsing strain in the transition state involving 1 .

1H, 13C and 199Hg NMR studies of the —NHCS-containing ligands with mercuric halides

Abstract The reaction of mercury(II) halides with imidazolidine-2-thione, 1,3-diazinane-2-thione and 1,3-diazepine-2-thione yielded complexes of stoichiometry HgL 2 Cl 2 and HgL 2 Br 2 . The C(2) resonance of all thione ligands shifted more for HgBr 2 complexes compared with HgCl 2 . The 199 Hg NMR chemical shift range is within −805 to −1008 ppm for HgL 2 Cl 2 complexes and −1124 to −1394 ppm for all HgL 2 Br 2 complexes. Also 13 C and 199 Hg NMR chemical shifts are compared for five-, six- and seven-membered ligands after complexing with mercuric halides.

1,3-DIPOLAR CYCLOADDITION REACTIONS OF 1-AZA-1-CYCLOOCTENE 1-OXIDE

The stereochemistry and reactivity of the cycloaddition reactions of eight-membered cyclic nitrone (4) with several alkenes have been studied. The concentrated solution of the cyclic nitrone undergoes polymerization to give acyclic polynitrone (15). The nitrone 4 is found to be less reactive than its seven-membered counterpart. Barrier to nitrogen inversion in one of the cycloaddition product, a 85 fused ring system, was determined to be 55.4 kJ/mol.

Synthesis and Cycloaddition Reactions of 2,3,4,5-Tetrahydropyrazine 1-Oxide

Abstract The stereochemistry and reactivity of the cycloaddition reactions of a heterocyclic nitrone, 2,3,4,5,-tetrahydropyrazine 1-oxide, have been studied. The heterocyclic nitrone is found to be more reactive than its carbocyclic counterpart. The nitrone underwent regio- and stereo-selective cycloaddition reaction with several alkenes to afford bicyclic isoxazolidines efficiently. Barriers to nitrogen inversion in the cycloadducts have been determined.

CYCLIC NITRONE-ETHENE CYCLOADDITION REACTIONS

Abstract Addition reactions of ethene onto several cyclic nitrones afforded [n,3,0]heterobicyclicalkanes devoid of any substituents in the ring skeleton. These fused ring systems with a bridgehead nitrogen, capable of undergoing nitrogen inversion, allowed us to determine the stereochemistry of the ring fusion and the thermodynamic stability of the cis, trans isomers. Some of the cycloadducts on peracid induced ring opening gave a new series of nitrones capable undergoing further cycloaddition reactions.

15N NMR studies of the binding of C15N− with gold(I) drugs

15N NMR studies of the interaction of 15N cyanide ion with gold(I)-thiomalate (Autm) and gold(I)-thioglucose (Autg) have been carried out at pH* 7.40. The chemical shifts of the two 15N ions containing species Au(C15N)2- and RS-Au-C15N- (where RS- = tm- or tg-) were identified at 265.94 and 260.30 ppm, respectively. From the broadened 15N NMR signals, approximate life times of the RS-Au-CN- species were calculated.

CENTRAL SAUDI ARABIAN CRUDE OILS: A GEOCHEMICAL INVESTIGATION

ABSTRACT A suite of Paleozoic oils from Central Arabia was studied in order to evaluate conventional hopane and sterane biomarkers, as well as non-conventional markers such as phenanthrene and its methylated isomers. Because it was uncertain whether conventional biomarkers would be found in these light oils, additional analyses were performed on the oils for correlation purposes. These include light-hydrocarbon and mid-range micro-scale correlation techniques. Paleozoic oils and condensates from several fields from Central Arabia as well as Paleozoic condensate and two Jurassic oils from the Eastern Province (for comparison) were studied. Bulk properties, such as API gravity, percent sulfur, and nitrogen content were determined. The oils and condensates were then fractionated into their major compound classes: saturates, aromatics, polars, and asphaltenes. The full range gas chromatographic analysis of the saturate and aromatic fractions did not permit meaningful distinctions for bimodal distribution of normal alkanes or identification of aromatic compounds. Micro-scale correlation technique was used to correlate mid-range hydrocarbons and the mid-range star diagrams (MRSD) are drawn. The MRSD showed that all Paleozoic fluids (Central Arabian oils) follow patterns that are different from those followed by the Eastern Province. Bulk properties, pristane/phytane ratios, methyl penanthrene ratio (MPR), and calculated reflectance (% R c) values showed that Paleozoic oils from Central Arabia differ significantly from Jurassic oils of the Eastern Province. Central Arabian Paleozoic oils and condensates are high-API gravity, exceedingly low sulfur, low nitrogen and low metals fluids. They have pristane/phytane ratios that are greater than one indicating dysoxic conditions at the time of deposition of their source rocks. Their MPR and % R c values are indicative of differences in timing of generation from the source rock as well as in maturity and, perhaps most significantly, indicative of post-generative alteration such as water washing. Eastern Province Jurassic oils are: medium-gravity, high sulfur, high nitrogen crude oils. They have pristane/phytane ratios that are less than one indicating highly reducing conditions at the time of source rock deposition. Their MPR and % R c values are indicative of generation from a source rock that was at peak oil maturity (VRe ≈ 0.80–1.0%).

Nitrogen inversion and N–O bond rotation in some hydroxylamine and isoxazolidine derivatives

A series of trisubstituted hydroxylamine derivatives, both cyclic and acyclic, has been prepared. The energy barriers in these hydroxylamines are found to be dominated either by nitrogen inversion or N–O bond rotation depending on the nature of the substituents attached to the nitrogen. In several series of compounds, having XC6H4CH2 substituents attached to nitrogen, Hammett free energy correlations are obtained with positive ρ values, indicating increased electron density at the transition state for the inversion process. Isoxazolidines with C(5) ethoxy substituents demonstrate a strong anomeric effect.