Martha Höhne

Selective Reductions of N,N-Bis{chloro(aryl)-phosphino}-amines Yielding Three-, Five-, Six-, and Eight-Membered Cyclic Azaphosphanes

To date, a plethora of λ3 -P nitrogen-containing compounds is known. A large number of them are used as ligands in coordination chemistry and homogeneous catalysis. PN-containing compounds tend to build up cyclic moieties, which have received less attention in regard to their application as ligands in transition metal chemistry. Hence, different dehalogenation reactions of N,N-bis{chloro(aryl)-phosphino}-amines have been developed to synthesize different P-N-P containing cyclic compounds. Their coordination behavior to groupu2005VI transition metal carbonyls was explored.

Synthesis of 1,2,4-triaza-3,5-diphospholidines

Abstract1,2,4-Triaza-3,5-diphospholidines were synthesized by highly selective cyclization reactions between N,N-bis[chloro(phenyl)phosphino]methylamine and 1,2-disubstituted hydrazines. Three examples of molecular structures are discussed against the background of configurational isomers and the potential of the title compounds as versatile cyclic ligands with chelating P–N–P motif.Graphical abstract

1,1-Bis(diphenylphosphoryl)hydrazine

The title compound, C24H22N2O2P2, contains a diphosphazane backbone, as well as a hydrazine entity. The P—N—P diphosphazane unit and the N-amine N atom are almost coplanar, and the O atoms of the Ph2P(O) units are oriented trans to each other with respect to the P⋯P axis. In the crystal, centrosymmetrically related molxadecules are linked into dimers by pairs of N—H⋯O hydrogen bonds, forming rings of graph-set motif R22(10).

1,1′-(Diphosphene-1,2-di­yl)bis­(2,2,6,6-tetra­methyl­piperidine)

The title compound, C18H36N2P2, crystallizes in the triclinic space group P-1 with two independent molxadecules in the asymmetric unit. Both molxadecules adopt a trans configuration of the tetraxadmethylxadpiperidine units along the P=P axis. The crystal packing is stabilized only by van der Waals interxadactions.

Di-μ-chlorido-bis­({4-[bis(trimethylsilyl)amino]-6-chloro-2,2,8,8-tetramethyl-5,7-bis(trimethylsilyl)-3,5,7-triaza-4,6-diphospha-2,8-disilanon-3-en-4-ido-κ2P,P′}palladium(II)) diethyl ether disolvate

The title compound, [Pd2(C18H54Cl2N4P2Si6)2Cl2]·2C4H10O, features a dinuclear chloride-bridged palladium complex bearing two equivalents of the novel monoanionic mixed valent (λ3-P)—N—(λ5-P) ligand. A metal catalyzed coupling of two aminoxadiminoxadphosphines and a shift of one chlorine from the metal to the phosphoxadrus results in the (λ3-P)—N—(λ5-P) ligand. The molxadecule contains a planar bimetallic Pd2Cl2 core with a crystallographic centre of inversion at the mid-point of the Pd⋯Pd line. The Pd atoms are in a distorted square-planar arrangement, where the P/Pd/P and Cl/Pd/Cl planes are twisted with respect to each other by a dihedral angle of 7.57u2005(4)°. The P—Pd—P bite angle is 71.380u2005(18)°. Intraxadmolecular C—H⋯Cl interxadactions are observed. In the crystal, the diethyl ether solvent molxadecule is disordered over two sites, with an occupancy ratio of 0.788u2005(5):0.212u2005(5).