Beiträge zur Chemie des Phosphors. 123. Synthese und Eigenschaften der Diphosphagermirane (t‐BuP)₂GePh₂ und (t‐BuP)₂GeEt₂

Abstract

Die ersten P2Ge‐Dreiring‐Heterocyclen, 1,2‐Di‐tert‐butyl‐3,3‐diphenyl‐1,2,3‐diphosphagermiran, (t‐BuP)2GePh2 (1), und 1, 2‐Di‐tert‐butyl‐3,3‐diethyl‐1,2,3‐diphosphagermiran, (t‐BuP)2GeEt2 (2), wurden durch [2+1]‐Cyclokondensation von K(t‐Bu)P—P(t‐Bu)K mit Diphenylgermaniumdichlorid bzw. Diethylgermaniumdichlorid synthetisiert. Als Nebenprodukte entstehen die vier‐, fünf‐ und sechsgliedrigen Cyclogermaphosphane (t‐BuP)2(GePh2)2 (3), (t‐BuP)3GeR2 (6 R = Ph; 7 R = Et), (t‐BuP)4GePh2 (5) und (t‐BuP)4(GePh2)2 (4) sowie (t‐BuP)4. Die Diphosphagermirane 1 und 2 konnten in 93‐ bzw. 100proz. Reinheit isoliert und eindeutig als Verbindungen mit P2Ge‐Ringgerüst charakterisiert werden. Von den Cyclogermaphosphanen 3—7 werden die 31P‐NMR‐Parameter mitgeteilt.

Ab initio and density functional study of structure and bonding of cage compounds containing boron, phosphorus and group 14 atomsElectronic supplementary information (ESI) available: optimized bond lengths and angles. See http://www.rsc.org/suppdata/nj/b3/b301191g/

“…35 Thus, no C s structure is obtained both for the P 2 (HB) 2 EH 2 cages and for the [(HB) 2 EH 2 ] fragments in this case. The P-E distances calculated are similar to those in the cage species (Me 2 Si) 6 P 4 , 36 (Me 2 Ge) 6 P 4 37 and (Me 2 Sn) 6 P 4 38 (2.244 A ˚, 2.308 A ˚, and 2.510 A ˚respectively). In general there is an almost linear dependence of key geometrical parameters of the cage upon the size and the orbital diffuseness of the element E. Plots of B-B and PÁ Á ÁP distances, as well as the P-E-P and the angle a between the two PEP planes, calculated at the B3LYP/3-21G++(d,p) level, versus the covalent radii of atom E 39 are given in Fig.…”

Synthesis of Cage Compounds Containing Boron, Germanium, and Phosphorus Atoms

“…The average P−Ge bond length, 2.324 Å, is, as expected, larger than the average P−Si bond length, 2.243 Å, in 17 due to the larger covalent radius of Ge. The P−Ge distance is slightly longer than the distance in (H 3 Ge) 3 P, 2.308(3) Å, but identical to the distance in the cage species (Me 2 Ge) 6 P 4 , 2.322(8) Å . The average P−B−P bond angle in 10 , 99.4°, is similar to the average value in 17 , 98.8°, but the P−Ge−P angle, 80.7(1)°, is slightly smaller than the P−Si−P angle, 84.8(1)°, in 17 .…”

“…The P-Ge distance is slightly longer than the distance in (H 3 Ge) 3 P, 2.308(3) Å, 18 but identical to the distance in the cage species (Me 2 Ge) 6 P 4 , 2.322(8) Å. 19 The average P-B-P bond angle in 10, 99.4°, is similar to the average value in 17, 98.8°, but the P-Ge-P angle, 80.7(1)°, is slightly smaller than the P-Si-P angle, 84.8(1)°, in 17. The sums of the internal angles at the phosphorus atoms in 10 are 219.9°(P1) and 218.3 (P2).…”