Abstract
The reactivity of the monoanionic amidinate ligand [(CH3) 3CNC(Ph)NSiMe2NC(Ph)-NHC(CH3)3]Li (1) with a silyl amido side arm towards the early actinides, uranium and thorium, was investigated. While the salt metathesis reaction with ThCl 4(thf)3 afforded the bis(amidinate)thorium(iv) dichloride complex [(CH3)3CNC(Ph)NSi(CH3) 2NC(Ph)-NHC(CH3)3]ThCl2 (2) in high yield, the reaction of ligand 1 with UCl4 leads to a Lewis acid supported nucleophilic attack of an incoming ligand unit, yielding the trichloro uranium complex [(CH3)3CNC(Ph)Si(CH3) 2-N(C(CH3)3)C(Ph)NSi(CH3) 2NC(Ph)N-(C(CH3)3]UCl3 (4). The exposure of in situ formed complex 2 to wet THF solutions (<1% w of water), gave the mono(amidinate)Th(iv)(chloro)(bis-hydroxo) dimeric complex [(CH 3)3CNC(Ph)NSiMe2NC(Ph)NHC(CH3) 3Th(OH)2(Cl)]2·(3) as bright red needles, exhibiting extremely short Th-OH bond distances (1.741(5) Å and 1.737(5) Å). The reactivity of the thorium complex 2 in the ring opening polymerization (ROP) was studied, showing high activity. Thermodynamic and kinetic measurements were performed to shed light on the mechanism for the ROP. This journal is
Original language | English |
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Pages (from-to) | 11376-11387 |
Number of pages | 12 |
Journal | Dalton Transactions |
Volume | 43 |
Issue number | 29 |
DOIs | |
State | Published - 7 Aug 2014 |
Externally published | Yes |