Organometallic calcium and strontium borohydrides as initiators for the polymerization of ε-caprolactone and L-lactide: combined experimental and computational investigations.

[Ca(BH4)2(THF)2] (1a), a known compound, was easily prepared following a convenient new procedure from [Ca(OMe)2] and BH3·THF in THF. Reaction of 1a with KCp* (Cp* = (η(5)-C5Me5)) and K{(Me3SiNPPh2)2CH} in a 1 : 1 ratio in THF resulted in the corresponding dimeric heteroleptic mono-borohydride derivatives [Cp*Ca(BH4)(THF)n]2 (2a) and [{(Me3SiNPPh2)2CH}Ca(BH4)(THF)2] (3a), respectively. Both compounds were fully characterized and the solid-state structure of 3a was established by single crystal X-ray diffraction.

[Ln(BH4)2(THF)2] (Ln = Eu, Yb)--a highly luminescent material. Synthesis, properties, reactivity, and NMR studies.

The divalent lanthanide borohydrides [Ln(BH(4))(2)(THF)(2)] (Ln = Eu, Yb) have been prepared in a straightforward approach. The europium compound shows blue luminescence in the solid state, having a quantum yield of 75%. Nonradiative deactivation of C-H and B-H oscillator groups could be excluded in the perdeuterated complex [Eu(BD(4))(2)(d(8)-THF)(2)], which showed a quantum yield of 93%.

Bis(phosphinimino)methanides as non-innocent ligand in zinc chemistry: synthesis and structures.

Reactions of the bis(phosphinimino)methane {CH2(Ph2PNSiMe3)2} with the zinc dihalides ZnCl2 and ZnI2 afforded the corresponding bis(phosphinimino)methane complexes [{(Me3SiNPPh2)2CH2}ZnCl2] (1) and [{(Me3SiNPPh2)2CH2}ZnI2] (2). In contrast, treatment of {CH2(Ph2PNSiMe3)2} with ZnPh2 in toluene gave the bis(phosphinimino)methanide complex of [{(Me3SiNPPh2)2CH}ZnPh] (3). Further reaction of 3 with the heterocumulenes di(p-tolyl)carbodiimine and diphenyl ketene resulted via a nucleophilic addition of the methine carbon atom of the {CH(Ph2PNSiMe3)2}- ligand to the heterocumulenes in a C-C bond formation.