Synthesis of luminescent alkynyl gold metalaligands containing 2,2′-bipyridine-5-yl and 2,2′:6′,2-terpyridine-4-yl donor groups

[AuCl(SMe2) reacts with HC CR (R = bpyl = 2,2'-bipyridine-5-yl (1), phtpyl phenyl-4-(2,2': 6',2 ''-terpyridine-4-yl) (2)) and NEt3 (1:1:3) to afford the polymers [Au(C CR)](n) (R bpyl (3), phtpyl (4)). The new alkyne HC Cphccbpyl (5, phccbpyl = 4-C6H4C Cbpyl) has been prepared by Sonogashira coupling of 4-Me3SiC CC6H4I and I followed by desilylation of the resulting alkyne 4-Me3SiC Cphccbpyl. The alkynyl Au(I) complexes [Au(C CR)L] (R = bpyl, L = PPh3 (6), PTol(3) (7, Tol = 4-MeC6H4), PEt3 (8); R = phtpyl, L = XyNC (9), PPh3 (10); R = phccbpyl, L = PPh3 (11)) have been prepared by reacting: (1) 3 or 4 with L or (2) the corresponding alkyne 1, 2, or 5 with [Au(acac)(PPh3)] (acac = acetylacetonato). The reaction of 3 or 4 with diphosphines ,gives [(Au(C CR)}(2)(mu-Ph2P(CH2)(x)PPh2)] (R = bpyl, x = 1 (12), 2 (13), 4 (14), 10 (15); R = phtpyl, x = 10 (16)). ESI mass spectrometric studies show that complexes 12-14 are in equilibrium with the salts [Au-3(C Cbpyl)(2)(mu-Ph2P(CH2)(x)PPh2)(2)][Au(C Cbpyl)(2)], although only when x = 1 (17) was a significant concentration of the salt detected by NMR spectroscopy and isolated. The anionic complexes PPN[Au(C CR)(2)] (R = bpyl (18), phtpyl (19), or phccbpyl (20)) have been prepared by reaction of the corresponding alkynes with PPN[Au(acac)(2)]. Complexes 6, 10, 13, 14, 17, and 18 have been characterized by sing e-crystal X-ray diffraction studies. The alkynyl complexes are luminescent at room temperature, displaying dual emissions.