Stepwise and chemically reversible reduction of (μ-bmtz)MCl(η6-cym)2PF62 (M = Ru, Os; bmtz = 3,6-bis(2'-pyrimidyl)-1,2,4,5-tetrazine) with up to six electrons. Zeitschrift fuer Anorganische und Allgemeine Chemie, (627)7:1441--1453, 2001. [PUMA: ESR cymene;ruthenium dinuclear electrochem osmium pyrimidyltetrazine redn redn;spectroelectrochem ruthenium]