Three Phosphorus Atoms

No references could be located to any report of l-aza-2,3,4-triphosphorine, 1 -aza-3,4,5-triphosphorine, l-aza-2,3,5-triphosphorine, 1-aza-2,4,5-triphosphorine, l-aza-2,3,6-triphosphorine, or 1-aza-2,4,6-triphosphorine. 

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The X-ray structure of 4rCl(CO)(triphos)] confirms the trigonal-bipyramidal geometry of the Ir center, with the three phosphorus atoms occupying one axial and two equatorial positions and the Cl ligand in the remaining axial position.608... 

The dinuclear 2 3 species have been characterized in [Ag20u-dppm)3](OTf)2 and [Ag2(p-dppm)3](N03)2 (92), with the silver centers three coordinate by three phosphorus atoms of different dppm ligands.761,768 A tetranuclear species [Ag2(p-02CMe-0,0 )(p-02CMe-0)(p-dppm)]2 has been obtained by reaction of dppm with two equivalents of AgOAc. 762 The reaction of [Ag(Mes)]4 with dppm gives a trinuclear compound [Ag3(dppm-H)3] (93) in which the dppm ligand has been deprotonated with the formation of mesithylene. In the structure, two of the silver centers are three coordinate to three different phosphorus atoms and the other silver atoms is bonded to two carbon atoms.291,292... 

The molecular ion appears to retain its cyclic structure, but several ions with two or three phosphorus atoms can be detected.192 The fragmentation patterns of a number of dialkylphosphines (157) show initial loss of an alkyl group as a neutral particle formed by the transposition of hydrogen.193 Some six-membered cyclic phosphites (158 X = OEt, OPh, or Cl) have been studied.194 The mass spectra of a wide variety of phosphine sulphides (159 Z = Ph, Me, CH2Ph, COPh, NH2, N=CHPh, or... 

In the latter case each 14-electron CpCo group completes its valence-shell by sharing electron pairs with one other CpCO group and with three phosphorus atoms, consistent with its diamagnetic character and with the observed geometry. It is likely that many more such mixed clusters, incorporating both transition metals and main group element, will be developed in the future. 

Figure 2.7 Structure of adenosine tn phosphate. The molecule consists of adenine attached to ribose (forming adenosine) which is esterified to a triphosphate group with the three phosphorus atoms designated a, p and y. The primes ( ) on the carbon atoms of ribose differentiate the numbers from those of the adenine ring.

LiaP and NaaP have the same structure as NaaAs. Each phosphorus atom is surrounded by 5 alkali metal ions at the comers of a trigonal bipyramid. The lattice contains two types of alkali metal atoms. One sort is surrounded by a trigonal prism of other alkali metal ions, in which the centres of the three vertical faces of the prism are occupied by three phosphorus atoms. The other type of alkali metal ion is surrounded by 4 phosphorus atoms in a distorted tetrahedron. Seven alkali metal ions are found at larger distances. In sodium phosphide the distance between the central phosphorus atom of the trigonal bipyramid and an axial sodium atom is 2.93 A and that between the phosphorus atom and an equatorial sodium atom 2.88 A... 

I. 0 A out of the plane of the three phosphorus atoms (Figure 11.26a).In contrast, the phenyl derivative, which is obtained from the reaction of PhPCl2 with (Meg 80)28 in C82, is comprised of a five-membered P382 ring with an exocyclic sulfur atom attached to one of the phosphorus centres (Figure... 

The first step in coupling ATP cleavage to any process is transfer of part of the ATP molecule to a nucleophile Y, usually by displacement on one of the three phosphorus atoms. The nucleophilic attack may be (a) on the terminal phosphorus (Py) with displacement of ADP or (b) on the internal phosphorus (Pa) with displacement of inorganic pyrophosphate. In the first case, Y-P03H is formed in the latter, Y-adenylyl (sometimes shortened to Y-adenyl) is formed. More rarely, displacement occurs (c) on the central phosphorus (Pp) with transfer of a pyrophospho group to the... 

Relevant structural data for selected mixed phosphine carbonyl complexes are shown in Table 5. In all these complexes the nickel(O) atom is four-coordinate in a pseudotetrahedral geometry with the Ni—CO linkage essentially linear, the Ni—C—O angles being in the range 173-178°. In complex (14) the np3 ligand bonds through the three phosphorus atoms and the r. kel is in a pseudotetrahedral environment.103... 

In all the complexes shown in Table 9 (with one exception) the nickel atom is four-coordinated by two phosphorus atoms and by two carbon atoms in a distorted planar arrangement (24a). The plane containing the nickel and phosphorus atoms and the plane containing the nickel and the coordinated carbon atoms form a dihedral angle which varies between 4° and 27° (24b), depending on the coordinated alkene. In the [Ni(p3)(C2F4)2] complex (25) the nickel atom is five-coordinated by three phosphorus atoms of the tridentate ligand and two carbon atoms of tetrafluoroethylene. 

A typical structure of these so called triple-decker sandwich complexes is that of the complex [(p3)Ni -(j)3-P3) Ni(p3)](BPh4)2-2.5Me2CO (73). In each complex the trihapto P3 (or trihapto As3) groups form a bridge between the two Ni(p3) residues.292 Each nickel atom is thus six-coordinated by three phosphorus atoms from the ligand p3 and by three phosphorus atoms from the cyclo-P3 (or arsenic atoms from the cyclo-As ), which acts as a three-electron-donor ligand. 

This ylid, formed in reaction (9), belongs to a rare class of compounds, distinguished by three phosphorus atoms attached to a ylidic carbon atom. Their 3 1 P-NITR-data are given in Table I. The parent compound of this type may be obtained according to (10) by 3 independent routes. 

II) occurs readily at room temperature even in nonpolar solvents. Various tripodal tris-phosphine ligands have also been shown to attach all three phosphorus atoms providing [Ir(COD)P3]+ compounds. ... 

Molecular orbital calculations (CNDO/2) on cyclic SN3 species, SN3, SN3, indicate the cation is more stable than the anion and that c -orbitals play an insignificant role. Several tetrathiatetraphosphatricyclooctanes contain four-membered rings with three phosphorus atoms and one sulfur atom. " ... 

The ladder structures found in 5-block amides are common structural motifs in phosphides as well. Solvent free [LiP(SiMe3)2]6 displays such an arrangement in the solid state, with four five-coordinate and two four-coordinate P atoms and four three-coordinate and two two-coordinate Li atoms the Li—P distances range from 2.38 A to 2.63 A (see Figure 52)." Li4(/X2-PR2)20 3 PR2)2(TFIF)2, formed from the reaction of P(SiMe3)3 with Bu Li in TFIF, has a fused tricyclic (LiP)4 ladder skeleton. The Li atoms are three-coordinate, with each of the two terminal lithiums bound to two P atoms and one THF, while the two internal lithiums have three phosphorus atoms as neighbors (see Figure 53)." " In solution, there is no NMR evidence for Xi- P... 

Six-membered rings with three phosphorus atoms... 

Rings with three phosphorus atoms, one nitrogen, and one sulfur or selenium atom... 

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