Planar P6E6 (E = Se, S) macrocycles incorporating P2N2 scaffolds

Abstract

Oxidation of alkali metal derivatives of the dianions [E((t)BuN)P(μ-N(t)Bu)(2)P(N(t)Bu)E](2-) (E = S, Se) with I(2) produces 15-membered macrocycles in which a planar P(6)E(6) motif is stabilised by perpendicular P(2)N(2) scaffolds.

Spirocyclic, macrocyclic and ladder complexes of coinage metals and mercury with dichalcogeno P2N2-supported anions

“…22 The Au-Se bond lengths of 2.396(2)-2.419(2) Å in 13 are comparable to the corresponding values of 2.390(1)-2.395(1) Å) observed for the latter complex. 22 The P-Se distances of 2.173(5) Å and 2.221(3) Å are similar to those reported for 9Se (2.253(2)-2.262(2) Å) 10 and [(Ph 3 PSe) 2 Au][SbF 6 ] (2.173(1)-2.174(1) Å). 22 The 31 P NMR spectrum of 13 in toluene exhibits two doublets at 4.9 ppm ( 2 J (P,P) = 16.4 Hz; 1 J (P,Se) ≈ 657 Hz) and −57.6 ppm ( 2 J (P,P) = 16.4 Hz; 1 J (P,Se) ≈ 627 Hz).…”

“…10 Although the cavity of the ring in 9Se and 9S is too small to accommodate metal ions, we were inspired by the reports of Krossing et al on the stabilisation of selenium homocycles, cyclo-Se 6 , -Se 12 and -Se 19 , in Cu(I) and Ag(I) complexes 11 to investigate the coordination behaviour of 9Se in the presence of coinage metals, including possible ring transformations. However, the treatment of 9Se with silver(I) triflate Ag-[CF 3 SO 3 ] produced the ionic compound [Ag(1Se) 2 ][CF 3 SO 3 ] (10) in which the cation is a complex of Ag + with two neutral ligands 1Se. 12 In the light of this result we decided to take a different approach to the synthesis of macrocycles incorporating P 2 N 2 E 2 building blocks and coinage metals, namely metathetical reactions of 3Se and 3S with various M(I) reagents (M = Ag, Au).…”

A mixed-valent cyclodiphosphazane: Transition metal chemistry and cis/trans isomerisation

“…[11][12][13] The dichlorocyclodiphosphazanes, cis-{ClP(μ-NR)} 2 , have been effectively explored as building blocks in the synthesis of a large range of phosphorus-nitrogen macrocycles. [14][15][16][17][18][19][20] Cyclodiphosphazanes can exist as cis and trans isomers in solution as well as in the solid state (chart 1, A and B). 2 The ring conformations of these isomers can be established by single crystal X-ray diffraction studies or by 31 P NMR data, where the cis isomers show upfield chemical shifts compared to the trans analogues.…”

A planar dianionic ditelluride and a cyclic tritelluride supported by P2N2rings

“…5 The synthesis of these polychalcogen macrocycles involves the two-electron oxidation of the dianions 1a and 1b with I 2. We now report a detailed investigation of the oxidation of the tellurium analogue 1c that provides important insights into the initial oxidation process, as well as a notable difference in the 25 final outcome of the oxidation compared to that observed for 1a and 1b.…”

“…4 Recently, we have applied a mild oxidative approach to generate the trimers [( t BuN)P(μ-N t Bu) 2 P(N t Bu)(µ-E-E-)] 3 with a planar P 6 E 6 (E = S, Se) framework in which dichalcogenido (-E-E-) groups are linked by perpendicular 20 P V 2 N 2 rings. 5 The synthesis of these polychalcogen macrocycles involves the two-electron oxidation of the dianions 1a and 1b with I 2. We now report a detailed investigation of the oxidation of the tellurium analogue 1c that provides important insights into the initial oxidation process, as well as a notable difference in the 25 final outcome of the oxidation compared to that observed for 1a and 1b.…”