An experimental and theoretical study of the coordination and donor properties of tris-2-pyridyl-phosphine ligands

The coordination characteristics and donor/acceptor properties of a series of 2-pyridyl substituted phosphine ligands have been investigated using structural, spectroscopic and DFT calculational studies. A range of different coordination modes are observed in Mo and W carbonyl complexes of tris-2-pyridyl-phosphine ligands of the type P(2-py') (2-py' = substituted or unsubstituted 2-pyridyl group), including an unprecedented example exhibiting N,N',μ2-π coordination. DFT calculations were used to assess the relative donor/acceptor properties of a range of related 2-pyridyl-phosphine ligands with respect to PPh3 and PtBu3.

Organophosphorus chemistry based on elemental phosphorus: advances and horizons

The results of studies on the application of elemental phosphorus for the synthesis of important organophosphorus compounds are surveyed and summarized. Currently, this trend represents a synthetically, environmentally and technologically attractive alternative to classical organophosphorus chemistry based on toxic and corrosive phosphorus chlorides. Direct phosphination and phosphinylation of organic compounds with elemental phosphorus (discussed in the first part of the review) basically extend the range of available phosphines, phosphine chalcogenides and phosphinic acids and provides further development of their synthetic potential (discussed in the second part of the review). It is shown that the breakthrough in this area is largely due to the discovery of reactions of elemental phosphorus (white and red) with various electrophiles in superbasic suspensions and emulsions derived from alkali metal hydroxides and to the development of electrochemical, electrocatalytic and catalytic activation of white phosphorus.

The bibliography includes 299 references.

Facile synthesis of a nickel(0) phosphine complex at ambient temperature

The reaction of the bis(methoxy)-2-pyridyl-phosphine (MeO)₂P(2-py) with [Ni(MeCN)₆](BF₄)₂ leads to the unexpected, single-step reduction of Ni^II and the formation of a tetrahedral nickel(0) complex.

Highly soluble Cu(i)-acetonitrile salts as building blocks for novel phosphorus-rich organometallic-inorganic compounds

The synthesis of the air-stable and highly soluble Cu(i)-acetonitrile salts [Cu(CH3CN)3.5][FAl] (1) ([FAl] = FAl{OC(C6F10)(C6F5)}3) and [Cu(CH3CN)4][TEF] (2) ([TEF] = Al{OC(CF3)3}4) is presented. Compound 1 reacts with the organometallic polyphosphorus complexes [Cp2Mo2(CO)4(η2-P2)] (A) and [(Cp*Fe(η5-P5)] (B) and salt 2 reacts with B to form one new (3) and three unprecedented (4-6) phosphorus-rich Cu(i) dimers with the general formulas [Cu2(μ,η1:η1-A)2(η2-A)2][FAl]2 (3), [Cu2(μ,η1:η1-A)2(η1-CH3CN)4][FAl]2 (4), [Cu2(μ,η1:η1-B)2(η1-CH3CN)4][FAl]2 (5) and [Cu2(μ,η1:η1-B)2(η1-CH3CN)4][TEF]2 (6).

How Changing the Bridgehead Can Affect the Properties of Tripodal Ligands

Although a multitude of studies have explored the coordination chemistry of classical tripodal ligands containing a range of main-group bridgehead atoms or groups, it is not clear how periodic trends affect ligand character and reactivity within a single ligand family. A case in point is the extensive family of neutral tris-2-pyridyl ligands E(2-py)₃ (E=C-R, N, P), which are closely related to archetypal tris-pyrazolyl borates. With the 6-methyl substituted ligands E(6-Me-2-py)₃ (E=As, Sb, Bi) in hand, the effects of bridgehead modification alone on descending a single group in the periodic table were assessed. The primary influence on coordination behaviour is the increasing Lewis acidity (electropositivity) of the bridgehead atom as Group 15 is descended, which not only modulates the electron density on the pyridyl donor groups but also introduces the potential for anion selective coordination behaviour.

Coordination preference of hexa(2-pyridyl)benzene with copper(ii) directed by hydrogen bonding

Coordination modes of hexa(2-pyridyl)benzene ligand with copper(ii) ions were controlled by different solvents mainly due to hydrogen bonding.

Tris(2-pyridyl)phosphine as a versatile ligand for pnictogen acceptors

We report cationic complexes of arsenic and antimony with the tris(2-pyridyl)phosphine ligand. Chloride ion abstraction from the main group halide using TMSOTf in presence of the ligand gives [P(Pyr)₃Pn][OTf]₃, in which the trication adopts a Janus Head type complex with a C_3v symmetric cage structure and two apical lone pairs.