Citation classic

Pauling, L. This Week s Citation Classic Curr. Contents 1985, 25, 16. 

Citation classics are papers that are exceptionally often cited, e.g. 100 times or more. Try to identify one or more citation classics in the area of catalysis you are most interested in. How often do you think that the average paper in catalysis will be cited ... 

Adventures in Cationic Polymerisation, P.H. Plesch, Current Contents, 1989, 29, 16 (Citation Classic). 

Schwertmann, U. (1984a) The influence of aluminium on iron oxides. IX. Dissolution of Al-goethites in 6 M HCl. Clay Min. 19 9-19 Schwertmann, U. (1984b) Citation Classic, Current Contents, Agric. Biol. Envir. Sd. 15 No 22... 

Polymer rose bengal, or Sensitox I, was derived from this concept. It was, in the words of an inmortal reviewer, a "citation classic".17... 

The activity of a catalyst often depends on the type of sites that are present on the catalytically active particles. Hence, ideally one wants to know how atoms are distributed over terraces, edges, corners, etc. - a question that has long occupied the thoughts of many investigators of catalysis. Van Hardeveld and Hartog [17] addressed this problem by analyzing the different atom environments on a number of different crystal geometries, such as cubes and truncated octahedrons, as a function of their size, and their report from 1969 has subsequently become a true citation classic. 

The extent of muscle diseases can be followed by the decrease of ATP concentration. Surprisingly, I have one paper, which is a citation classic and that s the one where I showed the effect of metal ions on the NMR chemical shifts of P in ATP. It is now used even in vivo to find out how much magnesium there is by measuring the chemical shift of the phosphorus atoms in ATP. One can determine how saturated ATP is with magnesium. Now it s used to determine magnesium concentration in the brain. 

Eigen has also been interested in the chemical basis of the origin of life, which seems to be a very different question from his previous studies, in reality it is not. Two of his papers were named Citation Classics by Current Contents. One paper was Proton-transfer, acid-base catalysis, and enzymatic hydrolysis. Part I elementary processes. An ew. Chem. 1963, 75, 489 Int. Ed. En l. 1964, 5, 1-19. It was one of the most cited papers in the field. The German and the English versions have been cited more than 285 and 965 times, respectively, by 1990. Then Eigen worked on evolution and published another paper, Self-organization of matter and the evolution of biological macromolecules. Naturwissenschafien 1971, 58, 465-523. This paper was the most cited paper in that journal in over 490 publications by 1990. 

My second paper was also published in 1964. It appeared in the Proceedings of the Academy of Sciences of the USSR, and later it became a Citation Classic. 

For further studies a selective inhibitor of MAO-B was needed. We were lucky to discover in 1970 that (-)-deprenyl was the missing, highly selective inhibitor of MAO-B (Knoll and Magyar 1972). The compound was used thereafter as the specific experimental tool to analyze MAO-B. Our first paper that described this novel property became a citation classic 10 years later (Knoll J, This Week s Citation Classic, January 15, 1982). For several years the selective MAO-B inhibitory effect was at the center of our interest. It delayed the discovery of the drug s enhancer effect. It was the MAO inhibitory effect of the compound that led to the first clinical application of (-)-deprenyl. 

A citation classic is a highly cited publication as identified by the Science Citation Index (SCI). Each scientific discipline has its own publication and citation rates. Most fields require at least 400 citations before a paper becomes a citation classic, but papers in smaller fields qualify with as few as 100 citations. However, as we have seen in Table 1, computational chemistry papers rank competitively with those of any other field of chemistry. 

Each weekly issue of Current Contents often has an essay by authors of new citation classics. These cover a broad range of science. We mention here a few additional computational chemistry papers that recently attained this distinction. We have already mentioned the extended Htickel paper of Hoffmann. ... 

E. Garfield (with A. Willjams-Dorof and C. J. Fiscus), Curr. Contents, Phys. Chem. Earth Sci., 30(26), 5 (1990). The Most-Cited Papers of All Time. SCI 1945-1988. Part 2. The Second 100 Citation Classics. 

G. Nemethy, Curr. Contents, Phys. Chem. Earth Sci., 28(30), 16 (1988). This Week s Citation Classic. G. Nemethy and H. A. Scheraga, J. Phys. Chem., 66, 1773 (1962). The Structure of Wiiter and Hydrophobic Bonds in Proteins. III. The Thermodynamic Properties of Hydrophobic-Bonds in Proteins. 

D. E. Williams, C rr, Contents, Phys. Chem. Ear// 5V/., 30(11), 14 (1990). This Week s Citation Classic. D. E. Williams, /. Chem. Phys., 47, 4670 (1967). Nonbonded Potential Parameters Derived from Crystalline Hydrocarbons. 

They thereby demonstrated the generality of the method. They also emphasized that n appears to be an additive property, the value of which is relatively independent of the parent aromatic structure or the position of the substituent. Several of the publications by the Pomona group are recognized as citation classics in view of the number of citations they have received. 

Segel IH. Citation-classic - enzyme-kinetics - behavior and analysis of rapid equilibrium and steady-state enzyme-systems. Curr Contents/Life Sci 1987 14. 

The concept gradually became very popular and is now considered a citation classic. According to the Institute for Scientific Information my work on the modulus was referenced a total of 227 times during the period 1961-1977. 

Lipscomb [3]. The title paper published by Hoffmann in 1963 [2] was featured as a citation classic in Current Contents in 1989 [4], where Hoffmann described the background of the EH method in detail. The firm foundation of the EH method was given in the title paper [2] and in the subsequent three papers published under the general title of ""Extended Hiickel theory " in 1964 [5-7]. In the EH method the MOs y fj i — 1,2,..., w) of a system are constructed using a set of valence atomic orbitals X X2 %3 The effective one-electron Hamiltonian, determining the... 

Throughout the studies discussed above, there has been a close interplay between structural measurements and development of theoretical models of molecular electronic structure. Lipscomb s contributions have included topological description of the boron hydrides and fundamental theory. Several coworkers contributed in this area, but most notable is the work with Roald Hoffmann, which changed the way chemists approach the theory of molecules of interesting complexity (see, e.g., the comments in (2(5)). The extended Huckel method was developed in the Lipscomb s group by several people, including especially L. L. Lohr, Jr., and Roald Hoffman (see Roald s recollections in Current Contents Citation Classic, May 8, 1989). Although the method probably contributed more to chemistry than any other method imtil very recently, Lipscomb recalled decades after he introduced it that this method received intense criticism, even denouncement. More exact theory led to the first correct calculation of the rotational barrier in ethane (with R. M. Pitzer in 1963). 

The details of the catalytic mechanisms of glycosidic bond cleavage are now generally well established and have been extensively reviewed (55-69). The following discussion shall constitute a primer on the salient points of these mechanisms the reader is referred to the literature reviews as a source of more detailed information. Of these, Sinnott s 1990 citation classic (63), Zechel and Withers s lucid account (56), and the contemporary overview by Vocadlo and Davies (66) are ideal entry points. Specific reviews providing a summary of recent advances in the structure/function analysis of saccharide phosphorylases are likewise recommended (24,26,27). 

R. Hoffmann, J. Chem. Phys., 39, 1397 (1963). An Extended Huckel Theory. I. Hydrocarbons. See also, R. Hoffmann, Curr. Contents, Phys., Chem., Earth Set., 29, 20 (1989). Citation Classic A Simple Quantum Chemical Method. 

Ramachandran, G. N. (1990). This week s citation classic. Current Contents, 10,119. 

---