Aggregation of cobalt(III) complexes with single thiolato or selenolato group assisted by AgI ion:: Crystal structures of spontaneously resolved 1D coordination polymers [Ag{Co(aet or aese)(en)2}](NO3)3(aet=2-aminoethanethiolate, aese=2-aminoethaneselenolate)

The reactions of [Co(aet)(en)(2)](NO3)(2) (aet = 2-aminoethanethiolate) or [Co(aese)(en)(2)](NO3)(2) (aese = 2-amino-ethaneselenolate) with AgNO3 in a 2:1 ratio in water gave S- or Se-bridged (CoAgCoIII)-Ag-III-Co-I trinuclear complexes: [Ag{Co(aet)(en)(2)}(2)](NO3)(5) ([1a](NO3)(5)) and [Ag{Co(aese)(en)(2))(2)}(NO3)(5) ([1b](NO3)(5)), while the corresponding 1:1 reactions produced S- or Se-bridged ((CoAgI)-Ag-III), chain complex-polymers: [Ag(Co(aet)(en)(2))](NO3)(3) ([2a](NO3)(3)) and [Ag{Co(aese)(en)(2)}](NO3)(3) ([2b](NO3)(3)). While the mononuclear [Co(aet or aese)(en)(2)](NO3)(2) and the trinuclear [1a or 1b](NO3)(5) were racemates, the polymeric [2a or 2b](NO3)(3) crystallized as a conglomerate to give optically active crystals of Delta and Lambda isomers. The crystal structures of Lambda-[2a](NO3)(3).H2O and Lambda-[2b](NO3)(3).H2O were determined by X-ray crystallography. In Lambda-[2a](3+) or Lambda-[2b](3+), the S or Se atom in each octahedral Lambda-[Co(aet or aese)(en)(2)](2+) unit is bound to two Ag-I atoms to form a one-dimensional ((CoAgI)-Ag-III), zigzag chain. Each Ag-I atom in Lambda-[2a](3+) or Lambda-[2b](3+) is closely contacted with NO3- anions, which stabilizes the chiral chain structure. The crystal structure of [1a](5+) was also determined by X-ray crystallography for its ClO4- salt ([1a](ClO4)(5).2H(2)O), which established that [1a](5+) exists as a racemic compound containing both the DeltaDelta and the LambdaLambda isomers in the crystal. The optically active S- or Se-bridged complexes, LambdaLambda-[1a or 1b](5+) and Lambda-[2a or 2b](3+), were obtained by the use of Lambda-[Co(aet or aese)(en)(2)](2+) as the starting complex, indicating that the reactions with Ag+ proceed with retention of the absolute configuration of the Co-III chiral center.