SOME SPECTROSCOPIC REMINISCENCES

We review a number of essentially spectroscopic problems in this perso nal account. The structure of high-temperature species remains a topic of considerable broad interest. The binary fluorides of essentially e very element are stable as the isolated gas-phase molecular species. A s such they provide a means of comparing bonding with the entire perio dic table. The structural characterization of the binary fluorides, al though still incomplete, has provided a considerable insight into a va riety of bonding types. The formation of molecules in the interstellar medium has been a model for abiotic synthesis of complex species. A k inetic model based upon ion-molecule reactions as the predominant reac tion class appears to fit many of the observations, such as the polyat omic ion HCO+. The high abundance of carbon-chain compounds is attribu ted to the efficient formation of C+ by the reaction CO + He+ --> C+ O + He. The spectroscopic characterization of weakly bonded species h as led to a detailed knowledge of intermolecular potentials. The dynam ics of molecular complexes has been frequently novel. In particular th e concurrent breaking and making of weak bonds is observed in many spe cies.