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 1 followed by desilylation of the resulting alkyne 4-Me3SiCCphccbpyl. The alkynyl Au(I) complexes [Au(CCR)L] (R = bpyl, L = PPh3 (6), PTol3 (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(μ-Ph2P(CH2)xPPh2)] (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 [Au3(CCbpyl)2(μ-Ph2P(CH2)xPPh2)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 single-crystal X-ray diffraction studies. The alkynyl complexes are luminescent at room temperature, displaying dual emissions.

[AuCl(SMe2)] 与 HC≡CR（R = bpyl，即2,2′-联吡啶-5-基（1）；phtpyl，即苯基-4-(2,2′:6′,2′′-三联吡啶-4-基)（2））以及三乙胺（NEt3，投料比1:1:3）反应，得到聚合物[Au(C≡CR)]n（R = bpyl（3）、phtpyl（4））。新型炔烃HC≡Cphccbpyl（5，phccbpyl = 4-(苯乙炔基)-2,2′-联吡啶-5-基）可通过如下步骤制备：先使4-Me3SiC≡CC6H4I与1发生薗头偶联（Sonogashira coupling）反应，再对所得炔烃4-Me3SiC≡Cphccbpyl进行脱硅基化反应。炔基Au(I)配合物[Au(C≡CR)L]（R = bpyl时，L = 三苯基膦（PPh3，6）、三(对甲苯基)膦（PTol3，7，Tol = 4-甲基苯基（4-MeC6H4））、三乙基膦（PEt3，8）；R = phtpyl时，L = 二甲苯异氰（XyNC，9）、三苯基膦（10）；R = phccbpyl时，L = 三苯基膦（11））可通过两种路径合成：(1) 由配合物3或4与配体L反应；(2) 由相应炔烃1、2或5与[Au(acac)(PPh3)]（acac即乙酰丙酮合基（acetylacetonato））反应。配合物3或4与双膦配体反应，可得到[{Au(C≡CR)}2(μ-Ph2P(CH2)xPPh2)]（R = bpyl时，x = 1（12）、2（13）、4（14）、10（15）；R = phtpyl时，x = 10（16））。电喷雾电离质谱（ESI mass spectrometry）研究显示，配合物12~14与盐[{Au3(C≡Cbpyl)2(μ-Ph2P(CH2)xPPh2)2}][Au(C≡Cbpyl)2]存在动态平衡，但仅当x=1（对应产物17）时，可通过核磁共振波谱（NMR spectroscopy）检测到该盐的显著浓度，并成功分离得到。阴离子配合物PPN[Au(C≡CR)2]（R = bpyl（18）、phtpyl（19）或phccbpyl（20））可通过相应炔烃与PPN[Au(acac)2]反应制备。配合物6、10、13、14、17和18已通过单晶X射线衍射（single-crystal X-ray diffraction）完成结构表征。该类炔基配合物在室温下具有发光性能，呈现双重发射峰。