Taking TiF4 complexes to extremes - the first examples with phosphine co-ligands

Abstract

, (2011), 'Hypervalent neutral O-donor ligand complexes of silicon tetrafluoride, comparisons with other group 14 tetrafluorides and a search for soft donor ligand complexes' Dalton, (2008) 'The first examples of germanium tetrafluoride and tin tetrafluoride complexes with soft thioether coordination-synthesis, properties and crystal structures' Dalton; Michael Webster, (2006) 'Tin(IV) fluoride complexes with tertiary phosphane ligands-a comparison of hard and soft donor ligands'

Soft diphosphine and diarsine complexes of niobium(v) and tantalum(v) fluorides: synthesis, properties, structures and comparisons with the corresponding chlorides

“…12 For those phosphines containing aromatic groups, there are also π→π* transitions in the near-UV region. Comparisons with the corresponding [MCl 4 (diphosphine) 2 ][MCl 6 ] ( Table 2) show that the P(σ)→M(d) charge transfer bands occur at higher energy in the fluorides, an effect observed in other systems, 7,10 and expected due to the strong M-F bonding which raises the energy of the metal d-orbitals. The Cl(π)→M(d) charge transfer bands are observed in the near ultraviolet region.…”

“…[MF 4 (diphosphine) 2 ][MF 6 ] complexes Initial attempts to form complexes of alkyldiphosphines (L-L) (L-L = o-C 6 H 4 (PMe 2 ) 2 , Me 2 P(CH 2 ) 2 PMe 2 or Et 2 P(CH 2 ) 2 PEt 2 ) used reaction of the appropriate MF 5 with the diphosphine in anhydrous CH 2 Cl 2 solution, similar conditions to those used to make thioether complexes, 6,7 and diphosphine complexes of TiF 4 from [TiF 4 (MeCN) 2 ]. 10 However, this approach failed; the major products were phosphonium salts of the well known [MF 6 ] − anions, and some other unidentified species. It is likely that the CH 2 Cl 2 is activated towards reaction with the phosphines by the strong Lewis acidity of the pentafluorides.…”

Guanidinium Perfluoridotitanate(IV) Compounds: Structural Determination of an Oligomeric [Ti6F27]3– Anion, and an Example of a Mixed‐Anion Salt Containing Two Different Fluoridotitanate(IV) Anions

“…In the solid state these units can remain isolated, leading to trivial hexafluoridotitanate(IV) salts, or they can be linked by sharing fluorine ions, yielding larger oligomeric (0‐D geometry) or polymeric (1‐D, 2‐D and 3‐D) anions. So far, there are 18 structurally characterized fluoridotitanate(IV) anions: oligomeric [TiF 6 ] 2– , [Ti 2 F 10 ] 2– ,, [Ti 2 F 11 ] 3– , [Ti 4 F 18 ] 2– , [Ti 4 F 19 ] 3– , [Ti 4 F 20 ] 4– , [Ti 5 F 23 ] 3– , [Ti 8 F 36 ] 4– , [Ti 10 F 45 ] 5– , and polymeric ([TiF 5 ] – ) ∞ , ([Ti 2 F 9 ] – ) ∞ ,, , ([Ti 3 F 13 ] – ) ∞ , ([Ti 4 F 19 ] 3– ) ∞ , ([Ti 6 F 27 ] 3– ) ∞ , ([Ti 7 F 30 ] 2– ) ∞ , ([Ti 9 F 38 ] 2– ) ∞ , and two modifications of the ([Ti 8 F 33 ] – ) ∞ anion , . The geometries of the various anions were determined with X‐ray experiments on single crystals of pure inorganic and/or hybrid compounds.…”

Structural Characterization of a Fluorido‐Amide of Niobium, and Facile CO2 Incorporation Affording a Fluorido‐Carbamate

“…This results in a Nb 4 tetrahedron, six edges of which are bridged by six µ‐F ligands. A similar M 4 (µ‐F) 6 core is present in [Ti 4 (µ‐F) 6 F 12 ] 2– , [W 4 (µ‐F) 6 F 12 ] 2–[25] and [Al 4 (µ‐F) 6 F 12 ] 6– . The µ‐F bridges are perfectly symmetric and all the Nb–F[4c], and Nb–NMe 2 distances are as expected for octahedral Nb V complexes.…”