Coordination ambivalence and fluxional behavior in mono- and binuclear pentacarbonyltungsten complexes of pteridine and its deaza derivatives. Journal of Organometallic Chemistry, (369)1:83--103, 1989. [PUMA: tungsten fluxionality deaza complex;tungsten deriv;naphthyridine carbonyl deriv pteridine complex;triazanaphthalene]