Synthesis, Characterization, and Chiral Behavior of S-Bridged CoIIIPtIICoIII Trinuclear Complexes Composed of Bis(thiolato)-Type Octahedral Units cis(S)-[Co(aet)2(en)]+ and/or trans(N)-[Co( d -pen- N,O,S)2]- (aet = 2-Aminoethanethiolate, d -pen = d -Penicillaminate)