Reaction of Double Ylide C(PPh₃)₂ with [W(CO)₆] – Crystal Structures of [(CO)₅­W(CCPPh₃)] and [(CO)₅W{η¹‐O₂C₂(PPh₃)₂}] and Bonding Analyses of [TM­(CCPR₃)] Compounds

Abstract

The photochemically generated complex [(CO)5W(thf)] reacts with C(PPh3)2 (1) to provide the salt (HC{PPh3}2)2[W2(CO)10] (5) in high yield by abstraction of a proton from the solvent thf. With [W(CO)6], a slow reaction in benzene occurs to give a mixture of [(CO)5W{O2C2(PPh3)2}] (6) and the heterocumulene (phosphonioacetylide) complex [(CO)5W(CCPPh3)] (7) by a Wittig type reaction. Both compounds were characterized by spectroscopic and X‐ray diffraction analyses. Theoretical density functional calculations reveal that the ligand CCPPh3 in 7 and in similar complexes is a strong σ‐donor but weak π‐acceptor.

Reactivity of Dicoordinated Stannylones (Sn0) versus Stannylenes (SnII): An Investigation Using DFT‐Based Reactivity Indices

“…Different theoretical and experimental studies report the complexation with different transition metal fragments, such as W(CO) 6 , W(CO) 5 , Ni(CO) 4 , Ni(CO) 3 , and AuCl 3b. 22–26 The divalent E 0 analogues, borylene complexes, (BH)L 2 , and N I and P I , labeled nitreones and phospheones, have recently been investigated both theoretically and experimentally 27–30. These compounds exhibit a very similar bent geometry, and reactivity towards Lewis acids and transition metals (AuCl).…”

Redox‐Induced Reversible PP Bond Formation to Generate an Organometallic σ4λ4‐1,2‐Biphosphane Dication

“…Within the alkynyl component, the shortening of the bond to phosphorus upon passing from 1 a to 4 a[PF 6 ] 2 is pronounced (0.047 ) but the associated CC bond lengthening is small, so the linker largely retains the structural characteristics of an alkyne. Simple [R 3 P + C C] ligands are considered to be strong sdonors and weak p-acceptors, [20] and the relative charge densities obtained here from B3PW91 DFT studies point clearly to dominant valence-bond structure for 4 a 2+ that has Fe II endgroups and a dicationic biphosphane functionality ( Figure 2; NPA charges computed for IVa 2+ : Q Fe À0.14, Q P + 1.45; for Ia: Q Fe À0.13, Q P + 0.96). [21] Cyclic voltammetry experiments performed on isolated 4 a,b[PF 6 ] 2 are consistent with those performed on 1 a,b.…”

Utilizing a zwitterionic approach for the synthesis of late transition metal – triphosphenium ion coordination compounds

“…10 Thorough bonding analyses on the isovalent triphosphenium ions and carbodiphosphoranes confirm the presence of "lone pairs" of electrons in frontier orbitals; 11,12 however, the latter have far more precedent to act as a ligand to transition metals and also to main group Lewis acids. [13][14][15][16][17][18][19][20] Of particular note is the ability of B to donate four electrons simultaneously to electron-deficient fragments such as {Ni(CO) 2 } (C), {BH 2 } + (D), {GeCl} + , and {PNR 2 } 2+ (E) that cannot be isolated with one traditional two-electron donor ligand (Fig. 1).…”