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

Abstract

The 1:1 reactions of [( i Pr2N)BP(H)B(N i Pr2)PLi·DME] and [(tmp)BP(H)B(tmp)PLi·DME] (tmp = 2,2,6,6-tetramethylpiperidino) with organylhalogermanes have been surveyed, and germyl-substituted diphosphadiboretanes of the type R2NBP(H)B(NR2)PGe(Cl)R‘2 (R2N = i Pr2N, tmp; Ge(Cl)R‘2 = Ge(Cl)Me2 and Ge(Cl)Ph2) have been isolated and characterized. Subsequent dehydrohalogenation of these compounds with t BuLi gave the new bicyclic cage compounds P2(BNR2)2(GeR‘2) (R2N = tmp, R‘=Ph; R2N = tmp, R‘ = Me) and/or oligomers [−(R2N)BP(H)B(NR2)PGeR‘2−] n (R2N = i Pr2N, R‘ = Me; R2N = tmp, R‘ = Me). In addition, the 2:1 reactions of [(R2N)BP(H)B(NR2)PLi·DME] with R‘2GeCl2 have been examined. In one case, the cage compound P2(BNR2)2GeR‘2 (R2N = tmp, R‘ = Ph) was obtained while a smaller alkyl group on Ge allowed formation of the bis(diphosphadiboretanyl)germanes [R2NBP(H)B(NR2)P]2GeR‘2 (R2N = i Pr2N, tmp; R‘ = Me). Two P2(BNR2)2(GeR‘2)·Cr(CO)5 (complexes R2N = tmp, R‘ = Ph, Me) were isolated and characterized. The molecular structures of the cage compound P2(Btmp)2GePh2 and the complexes P2(Btmp)2GeR‘2·Cr(CO)5 (R‘ = Ph, Me) were determined with single-crystal X-ray diffraction techniques. The structural and spectroscopic features are discussed in relation to those of other P2(BNR2)2(ER2) species.

Syntheses and spectroscopic investigation of some cyclophosphazanes: Analysis of pseudo‐triplet splitting

“…The chemistry of small inorganic heterocycles of the type (P N) 2 researches [1][2][3], mainly because such molecules are good starting materials for polycyclic inorganic and organometallic compounds [4,5]. The wide range applications of cyclophosphazanes in nucleophilic substitution reactions on P Cl bonds [6,7], coordination chemistry [8], and ring-opening polymerization reactions [9] causes a significant attraction to this area of chemistry.…”

Synthesis and Chemistry of Bis(borylphosphino)silanes and -germanes

“…The P atoms, in the apical positions, have a tetrahedral geometry with exo B(NR 2 ) 2 groups. The average P−B bond lengths in 11 , 1.934(4) Å, 13 , 1.928(6) Å, and 15 , 1.941(5) Å, are shorter than the average cage core P−B distances in P 2 (BN i Pr 2 ) 2 SiPh 2 , 16 1.973 Å, and in P 2 (Btmp) 2 GePh 2 (tmp = 2,2,6,6-tetramethylpiperidino), 17 , 1.973 Å, but they are typical of P−B single-bond lengths in a variety of (aminoboryl)phosphanes. − The boron atoms in the exo aminoboryl substituent groups are in a planar environment, and each group has a short and a long B−N bond. This effect has been observed in several (aminoboryl)phosphanes, − although its origin is not yet fully understood.…”

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/

“…Recently No ¨th and Paine have developed general assembly approaches for B x P y E z cage compounds and a number of five vertex cage compounds of the type P 2 (R 2 NB) 2 ER 2 , (E ¼ Si, Ge, Sn) have been prepared and structurally characterized. [11][12][13] The electronic structures of heterocapped five-vertex species of the type 1,5-X 2 B 3 H 3 (X ¼ N, CH, P, SiH, BH À ) have been discussed many times in the literature. 1,[14][15][16][17][18][19][20][21][22][23][24][25][26] One of the main goals of these works was the bonding description of these species in terms of either classical, 1a, or '' delocalized '' or nonclassical, 1b, electronic representations.…”

“…In this work, we describe the results of ab initio and density functional calculations for the five vertex cage compounds of the type P 2 (YB) 2 EH 2 , where E ¼ C, Si, Ge, Sn and Y ¼ H (2) and H 2 N (3). Although these systems have been systematically studied experimentally, [11][12][13] there were no theoretical data available. The molecular structures of all cages have been optimized at both levels of theory using the 6-311G++(d,p) and 3-21G++(d,p) basis sets and the variation of geometry as a function of the covalent radii and the diffuseness of the orbitals of the heteroatom E is examined.…”