β-Diketiminate Germylene-Supported Pentafluorophenylcopper(I) and -silver(I) Complexes [LGe(Me)(CuC6F5)n]2 (n=1, 2), LGe[C(SiMe3)N2]AgC6F5, and {LGe[C(SiMe3)N2](AgC6F5)2}2 (L = HC[C(Me)N-2,6-iPr2C6H3]2): Synthesis and Structural Characterization

Reactions of LGeMe (L = HC[C(Me)N-2,6-iPr(2)C(6)H(3)](2)) with 0.25 or 0.5 equiv of (CuC6F5)(4) gave the products [LGe(Me)CuC6F5](2) (1) and [LGe(Me)(CuC6F5)(2)](2) (2), respectively. In situ formed 1 reacted with 0.5 equiv of (CuC6F5)(4) to give 2 on the basis.of NMR (H-1 and F-19) spectral measurements. Conversely, 2 was converted into 1 by treatment with 2 equiv of LGeMe. Reactions of LGeC-(SiMe3)N-2 with 1 or 2 equiv of AgC6F5 center dot MeCN produced the corresponding compounds LGe[C(SiMe3)N-2]AgC6F5 (3) and (LGe[C(SiMe3)N-2] (AgC6F5)(2)}(2) (4). Similarly, 3 was converted into 4 by treatment with 1 equiv of AgC6F5 center dot MeCN and 4 converted into 3 by reaction with 2 equiv of LGeC(SiMe3)N-2. X-ray crystallographic studies showed that 1 contains a rhombically bridged (CuC6F5)(2), while 2 has a chain-structurally aggregated (CuC6F5)(4), both supported by LGeMe. Correspondingly, 3 showed a terminally bound AgC6F5 and 4 a chain-structurally aggregated (AgC6F5)(4), both supported by LGeC(SiMe3)N-2. Photophysical studies proved that the Ge-Cu metal metalloid donor acceptor bonding persists in solutions of 1 and 2 and Ge-Ag donor acceptor bonding in solutions of 3 and 4 as a result of the clear migration of their emission bands compared to those of the corresponding starting materials. Low-temperature (-50 degrees C) F-19 NMR spectral measurements detected dissociation of 1, 2, and 4 by the aggregation part of the CuC6F5 or AgC6F5 entities in solution. These results provide good support for pentafluorophenylcopper(I) or -silver(I) species having beta-diketiminate germylene as a donor because of its remarkably electronic and steric character.