Formation and X-ray Structures of Eight- and Sixteen-Membered Rings (ArC)nN2n(SPh)n [n = 2, Ar = 4-XC6H4 (X = Br, CF3); n = 4, Ar = 4-BrC6H4] and the Electronic Structures of (HC)2N4(SH)2 and (HC)2N4(SH)2^2- Journal Articles