The method selected for these determinations was that used by Albert for the determination of the second dissociation constant of 3-aminopyridine7~9 and which we previously used.6 It can be seen that the second p ' value of 1-aminoisoquinoline is in the same general area of those of 2aminopyridine (pK&' = -8.1) and 2-aminoquinoline (pKJ = -9.08).6 This is probably due to the close proximity of the two positive charges on the molecule and some interaction with the peri hydrogen atom. In the case of 3-aminoisoquinoline where there exists two adjacent positive charges, however, the second pK&' is considerably less than would be expected for an amino substituent a to the ring nitrogen. At first glance, the value obtained for the second pKa' of 4-aminoisoquinoline is larger than that for a /3-amino group, e.g., 3aminoquinoline (pK&' = -0.40),6 but it may be pointed out that this value is in the general area of 3-aminopyridine (pKJ = -1.5).6
The science of chemistry is almost unique among the sciences in being blessed with a single, thoroughly comprehensive key to the literature. That key, of course, is Chemical Abstracts. Hence, when there is a change in Chemical Abstracts format or indexing policy, or when Chemical Abstracts Service introduces a new product, science librarians who serve any part of the chemical community are professionally affected by these changes. This was evident when, in 1972, at the beginning of the ninth collective period for Chemical Abstracts, a number of new features were introduced. Perhaps the most obvious was the break‐up of the subject index into two parts — the general subject index and the chemical substance index. The over‐hauling of Chemical Abstracts nomenclature (particularly for organic compounds) at that same time was a more subtle, but probably also a more disorienting break with the past. The nomenclature changes were needed, however, and have been discussed and defended in an article by Donaldson and others.
Principles of online bibliographic information retrieval, and some practical work with major search systems, was offered as a component of a course dealing with information resources for university students in science and engineering at the University of California. As part of this program each student performed a search on a topic of his own choice and presented an oral report to the class on that search. Student reactions and attitudes are discussed, and some of the problems which emerged are described. The relevance to student needs of the online component of the course is also presented.
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