摘要:

Thymine dimers were obtained under ultraviolet irradiation. The major product is a trans-anti dimer linked by a cyciobutane ring. The infrared assignments and the mechanism of formation of this dimer are discussed in terms of an approximate force field and INDO data, respectively.

ISSN:0038-7010    

DOI:10.1080/00387018808082299

出版商:Taylor & Francis Group    

年代:1988

数据来源: Taylor

摘要:

Vycor Porous Glass (Thirsty Glass) has been studied as a reaction medium for several model chemical vapor detection reactions. It was also compared with Celgard 2400 microporous propylene film as a reaction medium. Using Thirsty Glass as the reaction support for the detector reagent 2,6-dichloroquinone-4-cnloroimide, 1-butanethiol was detected at concentrations as low as 0.1 ppm. With either 4,4′-bis(diethytamino)benzophenone oxime or 1,3-diisonitrosoacetone as the detector reagent, methanesulfonyl chloride was detected at concentrations in air as low as 1 ppm. When 4-(p-nitrobenzyl)pyridine was the detector reagent, high detection sensitivities for 2-chloroethylethylsulfide and dimethylsulfate were achieved only when a two-step test procedure was used.

ISSN:0038-7010    

DOI:10.1080/00387018808082300

出版商:Taylor & Francis Group    

年代:1988

数据来源: Taylor

摘要:

The ionic equilibria of anthralin were examined at 25°C in aqueous solutions varying in pH from 5.10 to 11.74. Despite the presence of three phenol groups, only one pKawas observed under a these experimental conditions and even at pH - 11.74 there was no spectroscopic evidence for the presumed second pKaPossible a causes for this result are discussed. The experimentally observed pKawas 9.06 which yielded a thermodynamic pKaestimate of 9.38. These results agreed well with one of two conflicting reports in the literature.

ISSN:0038-7010    

DOI:10.1080/00387018808082301

出版商:Taylor & Francis Group    

年代:1988

数据来源: Taylor

摘要:

Relative rate of HgX(B-State) formation due to collisions involving HgX2or CH3HgX (X˭Cl, Br, I) and N2(A) has been measured in a microwave discharge pumped NaN3vapors. These rates are K1: K2: K3: = 1: 6.4 : 8.6 and 1: 4.8 : 7.7 in case of HgX2+ N2(A) and CH3HgX + N2(A) collisions respectively. The K1, K2, and K3are the rates corresponding to Cl, Br, and I containing compounds.

ISSN:0038-7010    

DOI:10.1080/00387018808082302

出版商:Taylor & Francis Group    

年代:1988

数据来源: Taylor

摘要:

All the hydrogen disulfates M3H(S04)2(M = Na, K, Rb, Cs and NH4) display broad infrared spectra characteristic of very strong 0-H….0 hydrogen bonds overlapped by SO4group vibrations. Raman spectra (for compounds with M = Na, K, Rb) display the characteristic SO4modes more clearly. An ordered solid state at room temperature is suggested for M = Na and partially for K, while disorder is present when M = NH4Cs and Rb. Deuteration brings about ordering for M = K, NH4and in part when M = Rb, Cs. Order is also facilitated by lowering the temperature.

ISSN:0038-7010    

DOI:10.1080/00387018808082303

出版商:Taylor & Francis Group    

年代:1988

数据来源: Taylor

摘要:

The detection of copper in high salt solutions using flame atomic absorption spectrometry with discrete nebulization of microliter volumes compared to conventional continuous nebulization for sample introduction was investigated. Using continuous nebulization, a decrease in absorbance signal and uptake rate with increasing salt concentration, a detection limit of 0.02 μg/mL for copper, and precision deteriorating with increasing salt concentration in the 1–3% range was found. Discrete nebulization showed similar trends with decreasing absorbance signal with increasing salt concentration, but had the advantage that the microliter volumes used prevented clogging of the burner. At low microliter volumes and high salt concentrations, the precision deteriorated to around 10% and detection limit to 0.3 pg/mL. The technique was rapid, simple and did not produce memory effects.

ISSN:0038-7010    

DOI:10.1080/00387018808082304

出版商:Taylor & Francis Group    

年代:1988

数据来源: Taylor

摘要:

This is a scanned image of the original Editorial Board page(s) for this issue.

ISSN:0038-7010    

DOI:10.1080/00387018808082298

出版商:Taylor & Francis Group    

年代:1988

数据来源: Taylor