Detail of "2974-92-7"

Reference

Room temperature phosphorescence as a liquid chromatographic detection method for polychlorinated naphthalenes and biphenyls in complex matrixes

Room temperature phosphorescence as a liquid chromatographic detection method for polychlorinated naphthalenes and biphenyls in complex matrixes. Donkerbroek, J. J.; Gooijer, C.; Velthorst, N. H.; Frei, R. W. (Dep. Gen. Anal. Chem., Free Univ., Amsterdam 1081 HV, Neth.). Int. J. Environ. Anal. Chem., 15(4), 281-301 (English) 1983. CODEN: IJEAA3. ISSN: 0306-7319. DOCUMENT TYPE: Journal CA Section: 80 (Organic Analytical Chemistry) Section cross-reference(s): 9, 61 Quenched and sensitized room temp. phosphorescence in liq.Several substances with their cas registry numbers 2051-62-9 and 2974-92-7 may be metioned in this study. soln. (RTPL) techniques were used for the detection of polychlorinated naphthalenes (PCNs) and PCBs after liq. chromatog. sepn. The usefulness of these techniques to fingerprinting of com. Aroclor and Halowax mixts. in complex matrixes is shown. The complementary nature of these detection modes yields valuable information in addn. to UV detection. A signal inverter is proposed for linearization of the quenched RTPL signals. In this way linear calibration plots over >2 orders of magnitude can be obtained. Detection limits are generally in the low ng or subng concn. region. The application of RTPL detection techniques to com. PCN and PCB mixts. in surface water and urine is demonstrated. Pre-columns can be used to advantage for pre-concn. and clean-up of these types of samples. .

Conformational changes and S1 ? S0 origin transition energies: Polychlorinated biphenyls (PCBs)

All Rights Reserved. Conformational changes and S1 ? S0 origin transition energies: Polychlorinated biphenyls (PCBs). Hirokawa, Shoji; Imasaka, Tomoko; Oyakawa, Yoshikazu; Oishi, Masataka; Imasaka, Totaro (Department of Applied Chemistry, Graduate School of Engineering, Kyushu University, Nishi-ku, Fukuoka 819-0395, Japan). THEOCHEM, 772(1-3), 31-37 (English) 2006 Elsevier B.V. CODEN: THEODJ. ISSN: 0166-1280. DOCUMENT TYPE: Journal CA Section: 22 (Physical Organic Chemistry) Geometries and S1 ? S0 origin transition energies for biphenyl, deuterated biphenyl, and 24 PCBs were obtained using a Hartree-Fock (HF), a single-excitation CI (CIS), and a related CI method with doubles correction (CIS(D)). The HF and CIS geometries for biphenyl are in fairly good agreement with those obtained by a complete active space SCF (CASSCF) method.There are some reagents with their cas registry numbers 2974-92-7 and 41464-40-8 are used in this study. Calcd. results show that, in both S0 and S1 states of PCBs, the torsional angles and the inter-ring bond lengths can be classified according to the no. of ortho-chlorine atoms, n o-Cl. Probably the difference in electronic energy between the S0 and the S1 state also can be specified by no-Cl. The HF and CIS energies were cor. for electron correlation on the assumption that the electron correlation energy can be partitioned into constituent contributions. Calcd. S1 ? S0 origin transition energies agree with exptl. values within an error of 2%. This level of accuracy is comparable to that of the S1 ? S0 origin transition energy for biphenyl calcd. using the CASSCF method. The correction for electron correlation energy is largely due to contributions of the parent mol. and ortho-chlorine atoms. The present results will facilitate the anal. of electronic spectra of PCBs. .