[Bis(tetrahydrofuran–O)–bis(1,3–dialkyl–2–diphenylphosphanyl–1,3–diazaallyl)calcium] – Synthesis and Crystal Structures of Calcium Bis[phospha(III)guanidinates] and Investigations of Catalytic Activity |
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Authors: | Tareq  M.  A. Al–Shboul,Gritt Volland,Helmar Görls,Matthias Westerhausen Prof. Dr. |
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Affiliation: | Institute of Inorganic and Analytical Chemistry Friedrich–Schiller–Universit?t Jena August–Bebel–Str. 2 07743 Jena, Germany |
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Abstract: | The reaction of [(thf)4Ca(PPh2)2] ( 1 ) with diisopropyl– and dicyclohexylcarbodiimides yields the phospha(III)guanidinates [(thf)2Ca{RNC(PPh2)NR}2] with R = isopropyl ( 2 ) and cyclohexyl ( 3 ). The metathesis reaction of K{RNC(PPh2)NR} with anhydrous CaI2 also allows the synthesis of these phospha(III)guanidinate complexes 2 and 3 . For 2 a cis arrangement is observed whereas 3 crystallizes as trans isomer. The phospha(III)guanidinates act as bidentate chelate bases with an average Ca–N distance of 242.5 pm. The C–P bond length between the PPh2 fragment and the 1,3–diazaallyl unit is with values above 190 pm very large. The complexes 2 and 3 show a moderate catalytic activity in hydrophosphanylation reactions of dialkylcarbodiimides with diphenylphosphane. |
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Keywords: | Calcium Phospha(III)guanidinates Hydrophosphanylation Phosphanes Addition reactions |
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