Terminal Parent Phosphanide and Phosphinidene Complexes of Zirconium(IV)

Abstract

The reaction of [Zr(TrenDMBS)(Cl)] [Zr1; TrenDMBS=N(CH2CH2NSiMe2But)3] with NaPH2 gave the terminal parent phosphanide complex [Zr(TrenDMBS)(PH2)] [Zr2; Zr−P=2.690(2) Å]. Treatment of Zr2 with one equivalent of KCH2C6H5 and two equivalents of benzo‐15‐crown‐5 ether (B15C5) afforded an unprecedented example (outside of matrix isolation) of a structurally authenticated transition‐metal terminal parent phosphinidene complex [Zr(TrenDMBS)(PH)][K(B15C5)2] [Zr3; Zr=P=2.472(2) Å]. DFT calculations reveal a polarized‐covalent Zr=P double bond, with a Mayer bond order of 1.48, and together with IR spectroscopic data also suggest an agostic‐type Zr⋅⋅⋅HP interaction [∡ZrPH=66.7°] which is unexpectedly similar to that found in cryogenic, spectroscopically observed phosphinidene species. Surprisingly, computational data suggest that the Zr=P linkage is similarly polarized, and thus as covalent, as essentially isostructural U=P and Th=P analogues.

Metal–Ligand Multiple Bonding in Thorium Phosphorus and Thorium Arsenic Complexes

“…To isolate the terminal phosphinidene salt of 2a,t he deprotonation was performed in the presence of 2,2,2-cryptand, Equation (2). The yield, as determined by NMR spectroscopy, was nearly quantitativef or this reaction.…”

“…Abstract: The complexes (C 5 Me 5 ) 2 Th(EHTipp) 2 ,( E= Po rA s; Tipp = 2,4,6-triisopropylphenyl), provide al igand framework that results in facile access to rare Th-E multiple bonds. The reactiono f( C 5 Me 5 ) 2 Th(EHTipp) 2 with KN(SiMe 3 ) 2 ,p roceeds cleanly to the desired bridging phosphinidiide or arsinidiide complex, [{(C 5 Me 5 ) 2 Th(m 2 -ETipp)(m 2 -EHTipp)}K] 2 under ambient conditions. In the absence of ac helating agent, the potassium cation of one monomeric unit interacts with the aryl ring of as econd monomer to form ab ridged dimer.I nt he presence of 2,2,2-cryptand, the terminal phosphinidene complex, [(C 5 Me 5 ) 2 Th = PTipp(PHTipp)][K(2,2,2-cryptand)] is isolated.…”

“…[1][2][3][4] Phosphinidenesa nd phosphinidiides, as well as their lower congeners, arsinidenes and arsinidiides, are rare, with lesst han 50 examples in the literature. [1][2][3][4] Phosphinidenesa nd phosphinidiides, as well as their lower congeners, arsinidenes and arsinidiides, are rare, with lesst han 50 examples in the literature.…”

“…Phosphinidenes represent an important moiety as they are typically invoked in the catalytic cycles of hydrophosphination reactions as well as their interesti np roviding insighti ntom etalligand multiple bonding. [1][2][3][4] Phosphinidenesa nd phosphinidiides, as well as their lower congeners, arsinidenes and arsinidiides, are rare, with lesst han 50 examples in the literature. With respectt ofelement chemistry, several examples of thorium andu ranium phosphinidene, phosphinidiide, arsinidene, and arsinidiide complexes featuring short actinide-phosphorus or -arsenic bonds have been reported.…”

Molecular Mimics of Heterogeneous Metal Phosphides: Thermochemistry, Hydride‐Proton Isomerism, and HER Reactivity

“…Terminal phosphinidenes supported by U and Zr and sterically protected by bulky TREN variants were reported recently . The 31 P{ 1 H} chemical shifts for these PH moieties vary significantly, resonating at 2460 ppm for the U complex and at 247 ppm for the Zr compound, complicating phosphinidene assignment strictly on the basis of 31 P chemical shift. The chemical shift of the P‐bound proton is likewise highly variable, and in some of these complexes is (as in complex 6H) not observable by 1 H NMR spectroscopy .…”