MOLDA for Java, a platform-independent molecular modeling and molecular graphics program written in the Java language, is presented. The molecular coordinates in MOLDA, XMol and Protein Data Bank formats can be transferred to the VRML1.0/2.0 format file and can be viewed as a molecular model by using a VRML viewer on the World Wide Web. This program can also be used as an interface to the semi-empirical molecular orbital program MOPAC and the ab initio molecular orbital program GAUSSIAN 94.
A computational chemical investigation has been made into the mechanisms of the dehydration and the dehydrogenation of ethanol on six oxide catalysts (SiO2, TiO2, ZnO, MnO, MgO and CdO) using the DV-Xα method. Transition state models of the consecutive mechanism including ethoxide formation and the concerted mechanism proposed by Eucken and Wicke were computed. By comparing the computed results with experimental ones published in the literature, it was concluded that the consecutive mechanism is more reasonable than the concerted one. It was also concluded that the rate-determing step of the ethanol dehydration is for a β-hydrogen shift to a surface oxide ion and that the ease of theshift is a factor controlling the dehydration/ dehydrogenation selectivities of oxide catalysts.
A program to construct a fundamental and original starting material library to embody starting material-oriented retrosynthetic analysis in the AIPHOS system has been developed. The data in the library can be registered automatically from ACD, a commercial chemical structure database, by utilizing this program. This program recognizes synthetic equivalents to categorize functional groups. The resultant library is made up of a hierarchical structure using abstract graphs. The structure, the constructing method of the starting material library for AIPHOS and the registration results of data selected at random from ACD are described. In addition, a brief outline of AIPHOS is included.
Automatic analyzers for rainfall and Automatic water sampling apparatus areusually used as monitoring systems for acid rain. Instead of these apparatus, a simple system which measurs hydrogen ion concentration and electric conductivityin rainfall was devised by using a personal computer. This system consists ofpH meter, electric conductivity meter, automatic level controller and personalcomputer. This paper showes that the system was able to usefully measure hydro-genion concentration in rainfall.
MOLCONV [1, 2] that was a file conversion program for data formats of molecular structures in chemistry was transplanted from NEC PC-9801 for IBM PC or its compatible computers. Microsoft Visual Basic for MS-DOS sold in the USA was utilized as the compiler, because, IBM PC users were rapidly increasing with the popularity of Microsoft Windows in Japan; and this compiler was able to use a large property as Basic application until now. The Basic in USA was ordered using electronic mail and FAX, and imported. The price and the time to have Basic were a profitable deal over Japan. The main work for transplantation was replacement of functions or statements for Japanese two bytes character code with other functions or statements.