Gh. Duca et al./Chem.J. Mold.. 2008, 3 (1), 10-21[21] , .. .: , , 1988.[22] , .. .: - - , , 1990.[23] , .. .: , , 1995.[24] , ..; , .., . . : , 1984, 10, . 94-102.[25] Emerson, S.; Kalhorn, S.; Iacobs, L. et al. J. Geochim.Cosmochim Acta.1982, 46, 1073-1079.[26] , ..; , ..; , . . . .1984, 58; c.914-918.[27] Duca, Gh.; Gladchi, V.; Romanciuc, L. Procese de poluare i autoepurare a apelor naturale; CE USM: Chiinu,2002, p.3-140.[28] Gladchi, V.; Bunduchi, E. In Abstracts: Ecological <strong>chemistry</strong>, october 11-12, 2002, Chisinau, p. 42.[29] , ..; .., Mediul ambinat. Ministry <strong>of</strong> Ecology: Chisinau, 2003,3; pp. 4-11.[30] Monica, W. Lam and Scott A. Mabury. Aquatic Sciences. Vol. 67, Nr.2, 2005, p. 177-188.[31] Kpczysqi, M.; Czosnyka, A.; Nowakowska, M., J. Photo<strong>chemistry</strong> and Photobiology. 2004, 79(3), 259-264.[32] Prya, M.; Giridnar, M. J. <strong>of</strong> Photoch. and Photob. A: Chemistry. 2006, 179, 256-262.[33] Ksibi, M.; Zemzemi, A..; Bouqchina, R. J. <strong>of</strong> Photoch. and Photob. A: Chemistry. 2003, 159, 61-70.[34] , ..; , ..; , .. . . .1987, 51, 12; c. 3136-3139.[35] , ...; , .. . 1, 1988, c. 134-145.[36] , ..; , ..; .. IV . . . .: , . 1994; . 237-238.[37] . ; : , 1986; c.55-58.[38] Xiani Liu, Dong Xu, Feng Wu, Zhenhaun Lia, Jiantong Liu, Nansheng Deng., J. Photoch. and Photob., 2004,79(3), 259-264.[39] Duca, Gh.; Scurlatov, Yu. Ecological <strong>chemistry</strong>; Publishing Center MSU: Chisinau, 2002; pp. 154-196.[40] , ..; .. ;. . . .: , 2002, .I II.[41] Sharpless Charles, Seibold Deborah, Linden K., J. Aquat. Sci. 2003, 65, 359-366.[42] Borodaev, R., nal. tiin. ale USM, seria „tiine chimico-biologice”. CE USM: Chiinu, 2002; p.401-407.[43] Duca, Gh.; Goreaceva, N.; Romanciuc, L.; Gladchi, V., J. Intellectus., tiina: Chiinu, 1999, 4; p.62-68.[44] , .. .: - - , , 1996.21
Chemistry Journal <strong>of</strong> Moldova. Gh. Duca General, et al./Chem.J. Industrial Mold.. and 2008, Ecological 3 (1), Chemistry. 22-30 2008, 3 (1), 22-30PHYSICAL METHODS OF FAST REACTIONS INVESTIGATIONGheorghe Duca a , Natalia Secara b* , Daniela Duca caAcademy <strong>of</strong> Science <strong>of</strong> Moldova, 1 Stefan cel Mare str., MD-2001, Chisinau, Republic <strong>of</strong> Moldova;bInstitute <strong>of</strong> Chemistry, 3 Academy str., MD-2028, Republic <strong>of</strong> Moldova, Tel: (0373-22)7297;cLafayette College, Easton, PA, USA*Corresponding author: E-mail: natalia_secara@yahoo.comAbstract. This review presents the basic concepts <strong>of</strong> the methods used for investigation <strong>of</strong> fast reactions kinetics,such as: flow methods, with particular emphasis on the stopped-flow approach, NMR, ESR, electrochemicalmethods, with particular emphasis on the time resolved Fourier Transform electrochemical impedance spectroscopy,flash photolysis, and several others. It <strong>of</strong>fers a brief description <strong>of</strong> fast reactions commonly encountered in chemicalsystems, providing an insight into the possibilities <strong>of</strong> performing kinetic investigations <strong>of</strong> such reaction systems.Keywords: fast reactions kinetics, spectroscopy, relaxation, flow methods.IntroductionThe outstanding interest in investigating rapid reactions that burst out in the last decades <strong>of</strong> the last century isnowadays greatly supported by the development <strong>of</strong> new approaches and methodologies. Modern methods, formed onthe basis <strong>of</strong> classical ones, allow the discovery <strong>of</strong> precious information about elementary processes in various systems:chemical, biological, environmental, biochemical, real systems or models.A wide range <strong>of</strong> physical methods can be applied in order to perform kinetic investigations <strong>of</strong> rapid reactions,depending on the specificities <strong>of</strong> the reacting system. Further we will shortly present some <strong>of</strong> the basic concepts <strong>of</strong>physical methods <strong>of</strong> fast reactions investigation and new directions in the field <strong>of</strong> rapid reactions study.Fundamental aspects <strong>of</strong> rapid reactions’ researchUsually, fast reactions are divided into three categories, depicted in the figure below:0 131A A A PA A A P A 2 4 2 4A. B.0 3013E A EA EAP E 2 4C.Fig. 1. Multi-stage fast reactions.A. Type I complex reaction – a “simple” multi-stage reaction. B. Type II multi-stage reaction – cyclic, chain reaction.C. Type III multi-stage reaction – cyclic, catalytic reaction. Where: A * - active particle; X - intermediate substance;Preactionproduct;E – catalyst;(0) – reaction <strong>of</strong> reactants activation; (1, 3) – reactions that involve an active particle,intermediate substance on the formation <strong>of</strong> P;(2, 4) – reactions <strong>of</strong> A * , X, not yielding P.An example <strong>of</strong> type I complex reaction is the following transformation: 2Na + C 2H 4Cl 2 2NaCl + C 2H 4, whichinvolves one-stage reactions steps:*0. C 2H 4Cl 2 C 2H 4Cl 2*1. C 2H 4Cl 2+ Na NaCl + C 2•H 4Cl*2. C 2H 4Cl 2 C 2H 4Cl 23. C 2•H 4Cl + Na NaCl + C 2H 44. 2 C 2•H 4Cl C 4H 8Cl 222
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- Page 66 and 67: V. Mukhin et al./Chem.J.Mold. 2008,
- Page 68 and 69: Chemistry Journal of Moldova. N. Ku
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- Page 126 and 127:
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