Homoleptic, heteroleptic and mixed-valent thallium and indium complexes of multidentate chalcogen-centred PCP-bridged ligands
作者:Maarit Risto、Tristram Chivers、Jari Konu
DOI:10.1039/c1dt10646e
日期:——
The metathetical reaction of [Li(TMEDA)][HC(PPh2Se)2] ([Li(TMEDA)]1) with TlOEt in a 1 : 1 molar ratio afforded a homoleptic Tl(I) complex as an adduct with LiOEt, Tl[HC(PPh2Se)2]·LiOEt (7), which undergoes selenium–proton exchange upon mild heating (60 °C) to give the mixed-valent Tl(I)/Tl(III) complex [Tl][Tl(Se)C(PPh2Se)2}2]}∞ (8). Treatment of TlOEt with [Li(TMEDA)]2[(SPh2P)2CE′E′C(PPh2S)2] (3b, E′ = S; 3c, E′ = Se) in a 2 : 1 molar ratio produced the binuclear Tl(I)/Tl(I) complexes Tl2[(SPh2P)2CE′E′C(PPh2S)2] (9b, E′ = S; 9c, E′ = Se), respectively. Selenium–proton exchange also occurred upon addition of [Li(TMEDA)]1 to InCl3 to yield the heteroleptic complex (TMEDA)InCl[(Se)C(PPh2Se)2] (10a). Other examples of this class of In(III) complex, (TMEDA)InCl[(E′)C(PPh2E)2] (10b, E = E′ = S; 10c, E = S, E′ = Se) were obtained viametathesis of InCl3 with [Li(TMEDA)]2[(E′)C(PPh2E)2] (2b, E = E′ = S; 2c, E = S, E′ = Se, respectively). All new compounds have been characterized in solution by 1H and 31P NMR spectroscopy and the solid-state structures have been determined for 8, 9c and 10a–c by single-crystal X-ray crystallography. Complex 8 is comprised of Tl+ ions that are weakly coordinated to octahedral [Tl(Se)C(PPh2Se)2}2]− anions to give a one-dimensional polymer. The complex 9c is comprised of two four-coordinate Tl+ ions that are each S,S′,S′′,Se bonded to the hexadentate [(SPh2P)2CSeSeC(PPh2S)2]2− ligand in which d(Se–Se) = 2.531(2) Å. The six-coordinate In(III) centres in the distorted octahedral complexes 10a–c are connected to a tridentate [(E′)C(PPh2E)2]2− dianion, a chloride ion and a neutral bidentate TMEDA ligand.
[Li(TMEDA)][HC(PPh2Se)2] ([Li(TMEDA)]1)与TlOEt在1:1摩尔比下的类元反应生成了一种与LiOEt加合物的均配Tl(I)配合物Tl[HC(PPh2Se)2]·LiOEt (7),其在温和加热(60 °C)下发生硒-质子交换,生成混合价态的Tl(I)/Tl(III)配合物[Tl][Tl(Se)C(PPh2Se)2}2]}∞ (8)。在2:1摩尔比下,TlOEt与[Li(TMEDA)]2[(SPh2P)2CE′E′C(PPh2S)2] (3b, E′ = S; 3c, E′ = Se)反应生成了二核Tl(I)/Tl(I)配合物Tl2[(SPh2P)2CE′E′C(PPh2S)2] (9b, E′ = S; 9c, E′ = Se)。添加[Li(TMEDA)]1至InCl3时也发生了硒-质子交换,生成异配配合物(TMEDA)InCl[(Se)C(PPh2Se)2] (10a)。这类In(III)配合物的其他例子,如(TMEDA)InCl[(E′)C(PPh2E)2] (10b, E = E′ = S; 10c, E = S, E′ = Se),是通过InCl3与[Li(TMEDA)]2[(E′)C(PPh2E)2] (2b, E = E′ = S; 2c, E = S, E′ = Se)的类元反应获得的。所有新化合物在溶液中通过1H和31P NMR光谱进行了表征,并且通过单晶X射线晶体学确定了8、9c和10a–c的固态结构。配合物8由Tl+离子与八面体[Tl(Se)C(PPh2Se)2}2]−阴离子弱配位形成一维聚合物。配合物9c由两个四配位的Tl+离子组成,它们分别通过S,S′,S′′,Se键合到六齿配体[(SPh2P)2CSeSeC(PPh2S)2]2−上,其中d(Se–Se) = 2.531(2) Å。在扭曲的八面体配合物10a–c中,六个配位的In(III)中心与三齿[(E′)C(PPh2E)2]2−二阴离子、一个氯离子和一个中性二齿TMEDA配体相连。