《英语科学写作》课程教学资源：Writing Chemistry and Chemical Engineering Papers in English.doc_P16-P20

(R J. Molekaitis, I Murase, A. E. Martell.. Inorg. Nucl. chem. 1971, 33: 3353~3365 这是一篇争论性文章,作者首先概述了氨基膦酸类配体的发展史,着重指出了在发展过程中形成的两个学派,即美国的 Martel研究室和前苏联科学的 Kabachnik研究室,但对 Kabachnik等人所报道的两种配体和所得的结论提出质疑(主要是支持所得结论的证据不足) 为了弄清这一问题,作者重新合成并研究了这两种配体的络合性质文笔简练,直接提出争论的问题,不闪烁其词,这正是科学家严谨的学风 Ex 4 Introduction Two theoretical models are currently being used to account for electric dipole intensities of 4* radiative transitions in lanthanide complexes. The essential difference between these two models can be found in the roles played by the ligands in generating electric dipole strength in y 4f transitions In one of the models, the ligands role is to provide a non-centrosymmetric electrostatic potential at the lanthanide ion which, in turn, effects mixing between the even-parity 4f configurational states and higher -energy configurational states of odd panty localized on the lanthanide ion In thismodel, the ligand charge distributions remain unaffected by theradiation fied and are said to play a"static role in the electric dipole intensity mechanism. We shall refer to this model as the static coupling(SC)model. In the second model, the ligand charge distributions are dynamically coupled to the dipolar components of the radiation field producing an array of transient induced dipoles in the ligand environment, These induced dipoles are then presumed to couple to the(even-order )m ultipolar components of the lanthanide 4f-4f transitions via transition multipole (lanthanide)-tran-sitron dipole (lignadinteractions. In Don-centrosymmetric systems this coupling results in enhanced transition probabilities for the multipolar 4f4flanthanide transitions. We shall refer to this latter electric dipole intensity model cting the presumpt distributions are dynamically coupled to the radiation field and the lanthanide ion 4f-electron The most wiedly used theory of yf-4felectric dipole intensities was introduced in 1962by Judd 1] and Ofelt[2]. This theory, commonly referred to as the Judd-Ofelt theory, is based entirely on the static coupling model described above. The development of this theory marked the beginning of truly quantitative treatments of 4f-4f electric dipole intensities, and the phenomenological forms of this theory still provide the bases for most analyses carried out on ff-4fintensity spectra The basic ideas for the dynamic coupling model of yf-ff electric dipole intensities can be traced to the "inhomogeneous dielectric theory of hypersensitivity proposed by Jorgensen and Judd 3] n 1964. These same ideas, cast in a different formalism, have appeared more recently in the ligand polarization"theory of 4f-4fhypersesitiv ity proposed by Mason et al. [4-6]. Judd [7]has shown that the" inhomogeneous dielectric theory and the " ligand polarization"theory are simply formally different descriptions of the same physical mechanism or process. The dynamic coupling

(R. J. Molekaitis, I. Murase, A. E. Martell. J. Inorg. Nucl. chem. 1971, 33: 3353~3365) 这是一篇争论性文章，作者首先概述了氨基膦酸类配体的发展史，着重指出了在发展过程中形成的两个学派，即美国的 Martell 研究室和前苏联科学的 Kabachnik 研究室，但对 Kabachnik 等人所报道的两种配体和所得的结论提出质疑（主要是支持所得结论的证据不足）. 为了弄清这一问题，作者重新合成并研究了这两种配体的络合性质.文笔简练，直接提出争论的问题，不闪烁其词，这正是科学家严谨的学风. Ex. 4 Introduction Two theoretical models are currently being used to account for electric dipole intensities of 4f→4f radiative transitions in lanthanide complexes. The essential difference between these two models can be found in the roles played by the ligands in generating electric dipole strength in 4f →4f transitions. In one of the models, the ligands’role is to provide a non – centrosymmetric electrostatic potential at the lanthanide ion which, in turn, effects mixing between the even – parity 4f configurational states and higher – energy configurational states of odd parity localized on the lanthanide ion. In this model, the ligand charge distributions remain unaffected by the radiation fied and are said to play a “static ”role in the electric dipole intensity mechanism. We shall refer to this model as the static coupling (SC) model. In the second model, the ligand charge distributions are “dynamically ” coupled to the dipolar components of the radiation field producing an array of transient induced dipoles in the ligand environment, These induced dipoles are then presumed to couple to the (even – order ) m ultipolar components of the lanthanide 4f →4f transitions via transition multipole (lanthanide ) – tran-sitron dipole (lignad)interactions. In noon-centrosymmetric systems, this coupling results in enhanced transition probabilities for the multipolar 4f →4f lanthanide transitions. We shall refer to this latter electric dipole intensity model as the dynamic coupling (DC) model, reflecting the presumption that the ligand charge distributions are dynamically coupled to the radiation field and the lanthanide ion 4f –electron d i s t r i b u t i o n s . The most wiedly used theory of 4f →4f electric dipole intensities was introduced in 1962by Judd [1] and Ofelt [2]. This theory, commonly referred to as the Judd –Ofelt theory, is based entirely on the static coupling model described above. The development of this theory marked the beginning of truly quantitative treatments of 4f →4f electric dipole intensities, and the phenomenological forms of this theory still provide the bases for most analyses carried out on 4f →4f intensity spectra. The basic ideas for the dynamic coupling model of 4f →4f electric dipole intensities can be traced to the “inhomogeneous dielectric ”theory of hypersensitivity proposed by Jrgensen and Judd [3] in 1964. These same ideas, cast in a different formalism, have appeared more recently in the “ligand polarization ” theory of 4f →4f hypersesitivity proposed by Mason et al. [4-6]. Judd [7] has shown that the “inhomogeneous dielecteric ”theory and the “ligand polarization” theory are simply formally different descriptions of the same physical mechanism or process. The dynamic coupling

model described above is common to both of these theores Richardson and co-workers[8-12 have reported 4f-4f electric dipole intensity calculations which are based on a model which includes both static coupling(SC) and dynamic coupling(DC) effects. These calculations were carried out in conjunction with experimental studies, and it was found that satisfactory agreement between theory and experiment could be achieved only when both the SC and dC effects were taken into account. It was also found that in general the SC and DC mechanisms do not make simple additive contributions to the electric dipole strengths. This latter aspect of the combined SC/dC electric dipole intensity model is the subject of the present paper. (F.S. Richardson. Chem. Phys. Lett. 1982, 86(1): 47) 这是一篇关于跃迁理论模型的文章从60年代到80年代这方面的文章很多,出现了两种公认的模型因此,作者在第一段并未引用文献,而是直接叙述两种模型的理论依据及其差异第二段介绍了两种模型的代表作,即J-O理论模型和 Mason模型根据作者多年的工作,提出了将两种模型结合起来的方案,即本文的目的这种写法能使读者了解问题的全貌 Ex 5 Introduction The addition of surfactants to aqueous solutions of certain metal -dye complexes results substantial changes in the UV-visible spectrometry of these complexes Up to 60-fold increases in molar absorptivity(E)(I)and 150-nmred shifts in the wavelength of maximum absorbance(2max (2) have been reported among the systems summarized inrecent reviews(3-5). The mechanism of these surfactant-induced changes(and resulting sensitization of related analytical methods )is not ell understood. Improved understanding would greatly facilitate analytical exploitation and should also be useful in explaining surfactant-solubil izate interactions in other applications This report considers evidence distinguishing between the two major models for sensitization mechanisms: micellar solubilization and formation of temary complexes involving surfactant There is evidence in the literature supporting each major model. For example, Savin et al. (6) found that no spectroscopic changes were induced when the nonionic surfactant OS-20 was adde to the al--Chrome Azurol S metal -dyecomplex until the critical micelle concentration(CMC) was surpassed. Similar observations have been reported for several systems involving nonionic surfactants(7)and at least one system involving a cationic surfactant( 8). Additionally, in a recent udy in this laboratory involv ing a cationic surfactant(9), sensitization was found to be enhance by excess electrolyte. The degree of sensitization was observed to be dependent on the nature of the anion added, following the known order for counterion binding to a cationic micelle(10). This is markedly similar to salt effects observed in micellar catalysis(11). Similar effects are not expected in systems where interactions involve exclusively surfactant monomers(instead of micelles )(12) Thus the observed salt effects were interpreted as suggest ing that micellar interactions were at least

model described above is common to both of these theories. Richardson and co-workers [8-12] have reported 4f →4f electric dipole intensity calculations which are based on a model which includes both static coupling (SC) and dynamic coupling (DC) effects. These calculations were carried out in conjunction with experimental studies, and it was found that satisfactory agreement between theory and experiment could be achieved only when both the SC and DC effects were taken into account. It was also found that, in general, the SC and DC mechanisms do not make simple additive contributions to the electric dipole strengths. This latter aspect of the combined SC/DC electric dipole intensity model is the subject of the present paper. (F. S. Richardson. Chem. Phys. Lett. 1982, 86(1):47) 这是一篇关于跃迁理论模型的文章.从 60 年代到80 年代这方面的文章很多，出现了两种公认的模型.因此，作者在第一段并未引用文献，而是直接叙述两种模型的理论依据及其差异. 第二段介绍了两种模型的代表作，即J-O理论模型和 Mason 模型.根据作者多年的工作，提出了将两种模型结合起来的方案，即本文的目的.这种写法能使读者了解问题的全貌. Ex.5 Introduction The addition of surfactants to aqueous solutions of certain metal –dye complexes results in substantial changes in the UV-visible spectrometry of these complexes. Up to 60-fold increases in molar absorptivity () (1) and 150-nm red shifts in the wavelength of maximum absorbance (max) (2) have been reported among the systems summarized in recent reviews (3-5). The mechanism of these surfactant –induced changes (and resulting sensitization of related analytical methods ) is not well understood. Improved understanding would greatly facilitate analytical exploitation and should also be useful in explaining surfactant - solubilizate interactions in other applications. This report considers evidence distinguishing between the two major models for sensitization mechanisms: micellar solubilization and formation of ternary complexes involving surfactant monomers. There is evidence in the literature supporting each major model. For example, Savvin et al. (6) found that no spectroscopic changes were induced when the nonionic surfactant OS-20 was added to the Al3+−Chrome Azurol S metal –dyecomplex until the critical micelle concentration (CMC) was surpassed. Similar observations have been reported for several systems involving nonionic surfactants (7) and at least one system involving a cationic surfactant (8). Additionally, in a recent study in this laboratory involving a cationic surfactant (9), sensitization was found to be enhanced by excess electrolyte. The degree of sensitization was observed to be dependent on the nature of the anion added, following the known order for counterion binding to a cationic micelle (10). This is markedly similar to salt effects observed in micellar catalysis (11).Similar effects are not expected in systems where interactions involve exclusively surfactant monomers (instead of micelles )(12). Thus the observed salt effects were interpreted as suggesting that micellar interactions were at least

ble for the sensit izatio There is also significant evidence for the alternative model for surfactant sensitization, the formation of ternary complexes(4, 13-16), Pertiuent studies almost exclusively in-volve cationic surfactants. The hypothetical complexes are characterized by stoichiometries in which typically up to four surfactant monomers interact with the metal-dye complex. The induced spectral changes are essentially identical with those attributed elsewhere to micelles The concentrations at which concentrations at which spectral changes are noted are generally below the nominal CMC of the surfactants involved, although investigators occasionally overlook the lowering of the CMC by Much of the conflicting evidence in the literature couid be explained by a transition from monomer to micelle interactions, as surfactant concentration is increased. However, most studies cite evidence for one model or the other and do not carefully pursue the alternat ive. Thus, no such transition has been reported. This study was undertaken to establish, with representative metal-dye systems, whether micellar in teractions, ternary complex interactions, or both are responsible for surfactant sensitization The primary metal-dye system selected was the complex of Be whith the triphenylmethane dye Chrome Azurol S( CAS). Additionally, studies were carried out on the Cur? and Cu* complexes of CAS to determine whether the metal involved in the complex influences the sensitization behavior. The dependence of the visible spectrometry of these systems on sufactant concentration will be considered for a nonionic surfactant(Triton X-100, TX-100),an anionic surfactant(sodium dodecyl sulfate, SDs)and a cationic surfactant (hexadecyltrimethylammonium bromide, CTAB). The resrlts will be used to provide a model for the interactions involved in the sensitization process Such a model should remove much of the uncertainty which makes analytical application of the spectral sensitization susceptible to error arising from unrecognized matrix effects (9, 18) ( H Callahan& K D Cook. Anal. Chem. 1984, 56: 1632-1640) 这是一篇关于表面活性剂在光度分析中瓜机理的研究在本文之前,该领域已有许多报道及重要评论,应当说,这不是一个新课题,只是缺乏系统地归纳和比较作者在第一段中引用了两篇能反遇这类体系优越性的文献及三篇最新评论,在说明研究这类体系重要性的同时,指出有关反应机理尚不清楚本文的目的是要证明增敏机理的两种主要模型一一胶束增溶及三元络合物在第二、三段中,作者介绍了支持各种模型的主要报道,并对前人的工作予以肯定,引用了文献中的主要结论,当然,这些结论的观点不尽相同综合诸家的观点,作者提出了自己的研究思路、方法和体系,以及要证明的问题 §22 Introduction部分常用短语

partly responsible for the sensitization process. There is also significant evidence for the alternative model for surfactant sensitization, the formation of ternary complexes (4, 13-16), Pertiuent studies almost exclusively in-volve cationic surfactants. The hypothetical complexes are characterized by stoichiometries in which typically up to four surfactant monomers interact with the metal-dye complex. The induced spectral changes are essentially identical with those attributed elsewhere to micelles. The concentrations at which spectral changes are essentially identical with those attributed elsewhere to micelles. The concentrations at which spectral changes are noted are generally below the nominal CMC of the surfactants involved, although investigators occasionally overlook the lowering of the CMC by cosolutes (17). Much of the conflicting evidence in the literature couid be explained by a transition from monomer to micelle interactions, as surfactant concentration is increased. However, most studies cite evidence for one model or the other and do not carefully pursue the alternative. Thus, no such transition has been reported. This study was undertaken to establish, with representative metal-dye systems, whether micellar in teractions, ternary complex interactions, or both are responsible for surfactant sensitization. The primary metal-dye system selected was the complex of Be2+ whith the triphenylmethane dye Chrome Azurol S (CAS). Additionally, studies were carried out on the Cu2+ and Cu3+ complexes of CAS to determine whether the metal involved in the complex influences the sensitization behavior. The dependence of the visible spectrometry of these systems on sufactant concentration will be considered for a nonionic surfactant (Triton X-100, TX-100), an anionic surfactant (sodium dodecyl sulfate, SDS ) and a cationic surfactant (hexadecyltrimethylammonium bromide, CTAB). The resrlts will be used to provide a model for the interactions involved in the sensitization process. Such a model should remove much of the uncertainty which makes analytical application of the spectral sensitization susceptible to error a r i s i n g f r o m u n r e c o g n i z e d m a t r i x e f f e c t s ( 9 , 1 8 ) . (J. H. Callahan & K. D. Cook. Anal. Chem. 1984,56:1632~1640) 这是一篇关于表面活性剂在光度分析中瓜机理的研究.在本文之前，该领域已有许多报道及重要评论，应当说，这不是一个新课题，只是缺乏系统地归纳和比较. 作者在第一段中引用了两篇能反遇这类体系优越性的文献及三篇最新评论，在说明研究这类体系重要性的同时，指出有关反应机理尚不清楚.本文的目的是要证明增敏机理的两种主要模型——胶束增溶及三元络合物. 在第二、三段中，作者介绍了支持各种模型的主要报道，并对前人的工作予以肯定，引用了文献中的主要结论，当然，这些结论的观点不尽相同.综合诸家的观点，作者提出了自己的研究思路、方法和体系，以及要证明的问题. §2.2 Introduction 部分常用短语