Аннотация

The reduction of tetraphenyldiphosphine with two differently substituted samarocenes(II) proceeds via different pathways. With [SmCp 2(THF)2] (Cp = η5- C5Me5), the reaction had been known to result in the THF ring-opening product, [SmCp 2(O(CH2)4PPh2)], 3, owing to the instability of phosphido complex [SmCp 2(PPh2)] in the presence of THF. Complex 3 crystallizes from apolar solvents as dimeric or polymeric polymorph with butoxo-phosphine bridging ligands in both cases. In contrast, the phosphide [SmCp″2(PPh2)] (Cp″ = η5-1,3-C5H3 tBu2), 5, is not prone to ring-opening owing to insufficient space in the Sm coordination sphere for a THF ligand. Product 5 is inevitably accompanied by homoleptic complex [SmCp″3] 6 and dinuclear mixed-valent complex [SmIIICp″2(μ-PPh2)2SmIICp″] 7 as the further products of redox transformations and ligand exchange. The formation of 5-7 is rationalized by a sequence of initial coordination of one or two {SmIICp″2} fragments by P atoms and reductive elimination of PPh2· or Cp″·E radicals. Further reaction with another equivalent of [SmCp″2] results in the trapping the radicals and formation of all three products.

Язык оригиналаанглийский
Страницы (с-по)1287-1295
Число страниц9
ЖурналOrganometallics
Том36
Номер выпуска7
DOI
СостояниеОпубликовано - 10 апр 2017

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