Beiträge zur Strukturchemie phosphorhaltiger Ketten und Ringe

Abstract

The bicyclic phosphorus compound 2,3,4,6-Tetra-ter/-butylbicyclo[3.1.Ojhexaphosphane í-Bu 4 P 6 , C 16 H 36 P 6 crystallizes in the monoclinic space group P2Jn with a = 912.0pm, 6= 1383.8pm, c= 1951.4pm, β = 90.93° and Ζ = 4 formula units. The crystal structure has been worked out by single crystal X-ray methods and refined to R = 0.045 with 860 observed reflections.The molecule consists of a three-membered phosphorus ring connected to a five-membered ring by a common edge. The bicyclus has a chair-like phosphorus skeleton. The slightly distorted three-membered ring stands almost perpendicular to the five-membered ring. The latter adopts the conformation of an unusually flat, only slightly twisted envelope. The common edge with d (Ρ-P) = 219.7 pm and the average endocyclic bonding distance ¿(P -P) = 219.9 pm in the five-membered ring are almost equal, but different from the average endocyclic bonding distance <?(P-P) = 218.3 pm in the three-membered ring. The arrangement of the substituents tert-butyl is all-trans. The average bond lengths rf(P-C) = 190.4 pm and d(C -C) = 152.4 pm are as expected.

Selective Derivatization of a Hexaphosphane from Functionalization of White Phosphorus

“…P−Ga1−P: 78.3(4)°). Compared to R 4 P 6 in which the five-membered ring is almost planar with a fold angle α of 163.07°(for α, see Figure 1; R = tBu; 34 Cp* 4 P 6 : 142.8°1 8 ) in 3, it is much stronger and inversely kinked (av. −127.81(13)°), resulting in a boat conformation of the P 6 corpus.…”

“…In contrast, the fold angle β between the three-and five-membered ring is less acute in 3 (for β, see Figure 1; 3: av. 105.6(5)°; tBu 4 P 6 : 89.65°; 34 Cp* 4 P 6 : 88.83°1 8 ). Crystals of 4 were obtained by diffusion of n-pentane into a mixture of 3 and 4 in toluene.…”

From polygons to polyhedra through intermediate structures. A shape measures study of six-atom inorganic rings and clusters

“…50 Other 34-electron molecules analogous to bicyclo(3.1.0) hexane (3) contain P, As, Sb or Bi, with other elements appearing less frequently. Prototypical examples of this family are (PR 2 ) 4 (ER) 2 molecules (E = P, Sb, Bi), 53,57 whose shapes can be described as asymmetric chairs with the back narrower and much more bent than the footrest (Fig. 7d).…”