On the mechanisms of electride induced synthesis of ytterbium carbazolates, formation of coordination polymers by condensation and polymer degradation by chemical scissors

Dissolution of ytterbium metal in liquid ammonia in the presence of carbazole at low temperatures and subsequent treatment with N-phenylpiperazine gives single crystalline [Yb(CbZ)(2)(NH3)(4)].3Phpip (Cbz(-) = carbazolate anion, C12H8N-, Phpip = N-phenylpiperazine, (C6H5)C4H8NNH). The highly air and moisture sensitive crystals are prone to release ammonia but can be successfully shielded in the interior of large crystals of CbzH.Phpip, a co-crystallization of both ligands, whose crystal structure is also presented. Further heating transforms the monomeric molecules [Yb(CbZ)2(NH3)41 into dimeric [Yb-2(CbZ)(4)(NH2)(2)(NH3)(4)].3CbzH and their condensation accompanied by release of ammonia consequently leads to the coordination polymer (1)(infinity)[Yb-2(CbZ)(4)]. This reaction path is compared to a high temperature reaction route without electride formation. Synthesis in molten carbazole directly leads to the one-dimensional coordination polymer. Subsequent treatment with N-phenylpiperazinc yields dimeric [Yb-2(CbZ)(4)(PhPiP)(4)].2Phpip and monomeric [Yb(CbZ)(2)(PhpiP)(3)][Yb(CbZ)(3)(PhPiP)(2)], the final step of the degradation reaction. It can be shown that N-phenylpiperazine functions as chemical scissors at higher temperatures and as crystallization matrix at lower temperatures.