1H, 13C and 15N NMR spectral characterization of twenty-seven 1,2-diaryl-(4E)-arylidene-2-imidazolin-5-ones

1H, 13C and 15N NMR chemical shifts and couplings (n)J(H,C) in DMSO-d(6) at 30 degrees C have been determined for 1,2-diaryl-(4E)-arylidene-2-imidazolin-5-one derivatives 1-27. Their chemical shift assignments are based on PFG DQF 1H,1H COSY, PFG 1H,13C HMQC as well as PFG 1H,13C and 1H,15N HMBC experiments. For compounds 1-10 including aryl fluorine substituent(s) also the couplings (n)J(F,C) (n = 1 - 4) are reported.     

Sub-spectral analysis of the 100 MHz P.M.R. spectrum of 15N-pyrrole

A small range of compounds contain ions from two transition groups, 3d and 4f. Most of these enter an ordered antiferromagnetic state only at liquid helium temperatures, and the internal fields are 1 tesla or less. Experiments are suggested on various single crystals. Measurements by electron spin resonance on impurity ions in antiferromagnetic dysprosium phosphate show that similar compounds could be used for experiments on nuclear orientation with nuclear magnetic resonance.     

Effects of prolonged oral reading on F0, SPL, subglottal pressure and amplitude characteristics of glottal flow waveforms

The effects of prolonged (5x45 minute) reading (vocal loading) on fundamental frequency (F0), sound pressure level (SPL), subglottal (intraroral) pressure (p), and two glottal flow waveform parameters (AC amplitude of glottal flow, f, and negative peak amplitude of differentiated flow (d) of normal female and male subjects (N = 80) were studied. Two rest (morning and noon) and three loading (two in the morning and one in the afternoon) samples were recorded and analyzed. The glottal waveforms were obtained by inverse filtering of the acoustic pressure waveforms of speaking voice samples. The analyses were based on measurement and inverse filtering of the first stressed syllable of "paappa" words repeated 3x5 times for normal, as soft as possible, and as loud as possible phonation. In normal phonation the parameter values changed statistically significantly due to loading. In many cases the values obtained in the morning samples changed after the first loading session. This is interpreted as a vocal "warming-up effect." Especially in soft phonation p, d, and f were sensitive indicators of vocal loading. In both normal and soft phonation, the SPL, p, d, and f values tended to rise due to prolonged reading in the morning and afternoon samples, indicating increased effort (normal phonation) and a rise in the phonatory threshold (soft phonation). The lunch break vocal rest ("rest effect") considerably affected the parameter values in many cases.     

Detection of trypsin- and chymotrypsin-like proteases using p-nitroanilide substrates after sodium dodecyl sulphate polyacrylamide gel electrophoresis

Specific chromogenic p-nitroanilide substrates have proved useful for localizing proteolytic enzymes, such as trypsin, chymotrypsin and elastase after separation of agarose gel electrophoresis and when immobilized on nitrocellulose. This procedure was further developed for use with sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE). After SDS-PAGE, proteins were transferred electrophoretically to a nitrocellulose membrane. The membrane was incubated for 10–60 min with Bz-Ile-Glu-Gly-Arg-p-nitroanilide as a substrate for detection of trypsin-like proteases and with MeO-Suc-Arg-Pro-Tyr-p-nitroanilide for detection of chymotrypsin. The yellow p-nitroanilide released at the site of proteolytic activity was converted into a visible and stable red azo dye. By this method was identified and determined the molecular weight of a trypsin-like protease that occurs at high concentrations in mucinous ovarian tumour cyst fluid together with its specific inhibitor peptide, tumour-associated trypsin inhibitor (TATI). The method was also used to visualize trypsin and chymotrypsin in human pancreatic juice. Using the trypsin substrate, three proteolytic bands, corresponding to M_r of 22 000, 24 000 and 26 000 daltons, were visualized in pancreatic juice, while the proteolytic zones in cyst fluid had M_r of 25 000 and 28 000 daltons. With the chymotrypsin substrate, a band of 29 000 daltons was visualized in pancreatic juice, whereas no activity was detected in cyst fluid. By incubation of the blotted cyst fluid proteins with ¹²⁵I-labelled TATI, a pattern of bands at 25 000 and 28 000 daltons was detected identical to that obtained with the chromogenic substrate.     

E-2-Benzylidenebenzocycloalkanones. IV. Studies on transmission of substituent effects on C NMR chemical shifts of E-2-(X-benzylidene)-1-tetralones, and -benzosuberones. Comparison with the C NMR data of chalcones and E-2-(X-benzylidene)-1-indanones

Single substituent parameter (SSP) and dual substituent parameter (DSP) analyses were applied to study the transmission of substituent effects on selected ¹³C NMR chemical shifts of the cyclic chalcone analogues, E-2-(4′-X-benzylidene)-1-tetralones (2) and E-2-(4′-X-benzylidene)-1-benzosuberones (3). In order to study how the geometry of the cyclic chalcone analogues affects the transmission of substituent effects similar investigations with the respective chalcones (4) were also performed. The results obtained earlier with the five-membered analogue E-2-(4′-X-benzylidene)-1-indanones (1) were also involved in the comparisons. Geometry optimization of the unsubstituted 1a, 2a, 3a and 4a as well as the substituted 2 and 3 was performed by ab initio quantum chemical calculations. Both SSP and DSP analyses reflected that resonance effects contribute more to the chemical shift of C- (C2), while inductive effects primarily affect that of C-β (C10) of the enone moiety of all the four series. This latter effect, however, is far not as pronounced as that of the former one. It was found that DSP analysis data (ρ_F and ρ_R values) of transmission of substituent effects on the δC2 data can serve as a measure of choice to study the conformation (planarity) of the investigated enones in the four series.     

Copolymerization of vinylcyclohexane with ethene and propene using zirconocene catalysts

Vinylcyclohexane (VCH) was copolymerized with ethene and propene using methylaluminoxane‐activated metallocene catalysts. The catalyst precursor for the ethene copolymerization was rac‐ethylenebis(indenyl)ZrCl₂ ( 1 ). Propene copolymerizations were further studied with C_s‐symmetric isopropylidene(cyclopentadienyl)(fluorenyl)ZrCl₂ ( 2 ), C₁‐symmetric ethylene(1‐indenyl‐2‐phenyl‐2‐fluorenyl)ZrCl₂ ( 3 ), and “meso”‐dimethylsilyl[3‐benzylindenyl)(2‐methylbenz[e]indenyl)]ZrCl₂ ( 4 ). Catalyst 1 produced a random ethene–VCH copolymer with very high activity and moderate VCH incorporation. The highest comonomer content in the copolymer was 3.5 mol %. Catalysts 1 and 4 produced poly(propene‐co‐vinylcyclohexane) with moderate to good activities [up to 4900 and 15,400 kg of polymer/(mol of catalyst × h) for 1 and 4 , respectively] under similar reaction conditions but with fairly low comonomer contents (up to 1.0 and 2.0% for 1 and 4 , respectively). Catalysts 2 and 3 , both bearing a fluorenyl moiety, gave propene–VCH copolymers with only negligible amounts of the comonomer. The homopolymerization of VCH was performed with 1 as a reference, and low‐molar‐mass isotactic polyvinylcyclohexane with a low activity was obtained. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 6569–6574, 2006     

High-spin bands in117,119I and118Xe

Excited states in¹¹⁷I,¹¹⁸Xe and¹¹⁹I were populated in the reactions¹⁰⁶Pd+¹⁶O and^{108, 110}Cd+¹²C. The groundstate band in¹¹⁸Xe was observed to its (18⁺) member and the 11/2^? bands in¹¹⁷I and¹¹⁹I to their (35/2^?) and (43/2^?) members, respectively. The structure of the bands in the I isotopes is interpreted as aπ h _11/2 proton coupled to an even-even band structure in Xe, and the band crossings observed in¹¹⁸Xe and¹¹⁹I are interpreted in the Cranked Shell Model framework asAB _n ofv h _11/2.