Steric control of aggregation in neutral silver(I) thiolates, [AgSR]n. Crystal and molecular structures of [AgSCH(SiMe3)2]8, a discrete molecular biscycle of weakly interacting [AgSCH(SiMe3)2]4 units, and of [AgSC(SiPhMe2)3]3 and [AgSC(SiMe3)3]4, discrete molecular monocycles containing linearly coordinated silver(I) and doubly bridging mercapto sulfur donors from novel sterically hindered thiolate ligands. A comparison with the nonmolecular structure of [Ag4{SCH2(SiMe3)}3]n1