Influence of the PtAg Donor-Acceptor Bond and Polymorphism on the Spectroscopic and Optical Properties of Heteropolynuclear Benzoquin
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- 作者：Juan Fornié ; s ; Susana Ibá ; ñ ; ez ; Antonio Martí ; n ; Manuel Sanz ; Jesú ; s R. Berenguer ; Elena Lalinde ; Javier Torroba
- 刊名：Organometallics
- 出版年：2006
- 出版时间：August 28, 2006
- 年：2006
- 卷：25
- 期：18
- 页码：4331 - 4340
- 全文大小：227K
- 年卷期：v.25,no.18(August 28, 2006)
- ISSN：1520-6041
文摘
A new cyclometalated derivative, (NBu4)[Pt(bzq)(C6Cl5)2] (2) (bzq = 7,8-benzoquinolate), and threenovel polymetallic species containing donor-acceptor Pt
Ag bonds, (NBu4)[{Pt(bzq)(C6F5)2}2Ag] (3)and [{Pt(bzq)(C6X5)2}Ag(PPh3)] (X = F (4), Cl (5)), have been synthesized and characterized by X-raydiffraction methods. 3 is prepared by reaction of (NBu4)[Pt(bzq)(C6F5)2] (1) with AgClO4 in 1:1 or 1:0.5molar ratio, while 4 and 5 are the results of the reaction of the corresponding (NBu4)[Pt(bzq)(C6X5)2] (X= F (1), Cl (2)) precursors with [Ag(OClO3)(PPh3)] in 1:1 molar ratio. 3 has been found to crystallizein two forms: monoclinic (3a) and triclinic (3b), which differ not only in the conformation of the basicPt2Ag anion (anti and planar 3a, staggered and nonplanar 3b), but also in the crystal packing (
···extended structure 3a, and a stacked dimer 3b) and luminescence at 298 K (orange 3a, green 3b). At 77K, the orange band (568 nm) of 3a, attributed to a * excimeric emission, is not detected, and bothpolymorphs exhibit identical green emission (3LC/3MLCT). Spectroscopic study of 4 and 5 (UV-visand luminescence) was also performed to examine the role of the PtAg donor-acceptor bond. Themost significant feature is the blue shift observed in the low-energy UV absorption and the appearanceof two, close, distinct, structured emissions with short (487 4; 490 nm 5) and long (502 nm 4, 5) lifetime,but only in the solid state at 77 K.
Ag bonds, (NBu4)[{Pt(bzq)(C6F5)2}2Ag] (3)and [{Pt(bzq)(C6X5)2}Ag(PPh3)] (X = F (4), Cl (5)), have been synthesized and characterized by X-raydiffraction methods. 3 is prepared by reaction of (NBu4)[Pt(bzq)(C6F5)2] (1) with AgClO4 in 1:1 or 1:0.5molar ratio, while 4 and 5 are the results of the reaction of the corresponding (NBu4)[Pt(bzq)(C6X5)2] (X= F (1), Cl (2)) precursors with [Ag(OClO3)(PPh3)] in 1:1 molar ratio. 3 has been found to crystallizein two forms: monoclinic (3a) and triclinic (3b), which differ not only in the conformation of the basicPt2Ag anion (anti and planar 3a, staggered and nonplanar 3b), but also in the crystal packing (···extended structure 3a, and a stacked dimer 3b) and luminescence at 298 K (orange 3a, green 3b). At 77K, the orange band (568 nm) of 3a, attributed to a * excimeric emission, is not detected, and bothpolymorphs exhibit identical green emission (3LC/3MLCT). Spectroscopic study of 4 and 5 (UV-visand luminescence) was also performed to examine the role of the PtAg donor-acceptor bond. Themost significant feature is the blue shift observed in the low-energy UV absorption and the appearanceof two, close, distinct, structured emissions with short (487 4; 490 nm 5) and long (502 nm 4, 5) lifetime,but only in the solid state at 77 K.