Tetravalent Titanium, Zirconium, and Cerium Oxo and Peroxo Complexes Containing an Imidodiphosphinate Ligand

Abstract

Dinuclear Ti(IV), Zr(IV), and Ce(IV) oxo and peroxo complexes containing the imidodiphosphinate ligand [N(i-Pr(2)PO)(2)](-) have been synthesized and structurally characterized. Treatment of Ti(O-i-Pr)(2)Cl(2) with KN(i-Pr(2)PO)(2) afforded the Ti(IV) di-μ-oxo complex [Ti{N(i-Pr(2)PO)(2)}(2)](2)(μ-O)(2) (1) that reacted with 35% H(2)O(2) to give the peroxo complex Ti[N(i-Pr(2)PO)(2)](2)(η(2)-O(2)) (2). Treatment of HN(i-Pr(2)PO)(2) with Zr(O-t-Bu)(4) and Ce(2)(O-i-Pr)(8)(i-PrOH)(2) afforded the di-μ-peroxo-bridged dimers [M{N(i-Pr(2)PO)(2)}(2)](2)(μ-O(2))(2) [M = Zr (3), Ce (4)]. 4 was also obtained from the reaction of Ce[N(i-Pr(2)PO)(2)](3) with 35% H(2)O(2). Treatment of (Et(4)N)(2)[CeCl(6)] with 3 equiv of KN(i-Pr(2)PO)(2) afforded Ce[N(i-Pr(2)PO)(2)](3)Cl (5). Reaction of (Et(4)N)(2)[CeCl(6)] with 2 equiv of KN(i-Pr(2)PO)(2) in acetonitrile, followed by treatment with Ag(2)O, afforded the μ-oxo-bridged complex [Ce{N(i-Pr(2)PO)(2)}Cl](2)[μ-N(i-Pr(2)PO)(2)](2)(μ-O) (6). 6 undergoes ligand redistribution in CH(2)Cl(2) in air to give 5. The solid-state structures of [K(2){N(i-Pr(2)PO)(2)}(2)(H(2)O)(8)](n) and complexes 1-6 have been determined.

Synthesis, Structure, and Reactivity of a Tetranuclear Cerium(IV) Oxo Cluster Supported by the Kläui Tripodal Ligand [Co(η5‐C5H5){P(O)(OEt)2}3]−

“…Unfortunately,o wing to the disorder found for the hydroxo and Chem.E ur.J.2015, 21,16126 -16135 www.chemeurj.org peroxo ligands (for details, see the Experimental Section), the CeÀOb ond lengths for the peroxo and hydroxo ligandsi n2 are increased in their uncertainty. These distances are generally longer than the OÀO bonds found in [Ce IV 2 {N(iPr 2 PO) 2 } 4 (m 2 -h 2 :h 2 -O 2 ) 2 ]o f1 .412(6)-1.430(6) , [17] buthave ahigh degree of uncertainty. The outer peaks are stronger and separated by 1.425(14)-1.496(9) a nd correspondt of our bridging peroxy( m 2 -O 2 )g roups disordered over the six sites.…”

“…[17] The central electron density peaks of the disordered bridge sites are of lower intensity and are slightly displaced towards the Ce centers (Ce-O 2.153-2.297)a nd we assign them to two (m 2 -OH), again disordered over six sites. [17] The central electron density peaks of the disordered bridge sites are of lower intensity and are slightly displaced towards the Ce centers (Ce-O 2.153-2.297)a nd we assign them to two (m 2 -OH), again disordered over six sites.…”

“…[17,21] For example, [Ce IV 2 {N(iPr 2 PO) 2 } 4 (m 2 -h 2 :h 2 -O 2 ) 2 ]h as been obtained from the reaction of [Ce III {N(iPr 2 PO) 2 } 3 ]w ithH 2 O 2 . Relatively few molecular Ce IV peroxo complexes have been reported,a nd they are all dinuclear complexes containing the m 2 -h 2 :h 2 -O 2 2À ligand.…”

“…Selected bond lengths and angles are collected in Table 1. [17] and [Ce IV 2 (m-O)(dmop) 4 (mmp) 2 ]( dmop = 2-(4,4-dimethyl-4,5-dihydrooxazol-2-yl)propan-2-ol;m mp = 1-methoxy-2-methylpropan-2-ol)) [2.106 ], [18] but shortert han those for the m 4 -oxo ligands [av. The geometry Scheme2.Synthesis and reactivity of cluster 1.…”

“…The geometry Scheme2.Synthesis and reactivity of cluster 1. [17] The Ce-O-Ce angles for the m 4 -oxol igand in 1 are in the range 105.23(13)-114.02(14)8. Cores of the two independent molecular clusters, A (left) and B (right), in the asymmetric unit of 1.Drawn with 30 %p robability thermal ellipsoids.…”