Bis(tert-butylamido)- and bis(arylamido)cyclodiphosph(iii)azane complexes of Ti, V, Zr and Hf: ligand substituent effects and coordination number

New Bulky Bis(amino)cyclodiphosph(III)azanes and Their Titanium(IV) Complexes: Synthesis, Structures and Ethene Polymerization Studies

“…Methylalumoxane (MAO, 30 wt.% solution in toluene) was received from Borealis Polymers Oy. 2 (1), [16] cis-[(tBuNH)(tBuNP)] 2 , [21] cis-[(C 6 H 5 NH)(tBuNP)] 2 [12] and cis-[(tBuN) 2 (tBuNP) 2 ]Li 2 (THF) 2 [21] were prepared according to modified literature procedures. 2 (1) (0.65 g, 2.4 mmol), Et 3 N (1.4 mL, 1.93 g, 9.6 mmol) and 2-tert-butylaniline (0.75 mL, 0.71 g, 4.7 mmol) and separation of the resulting crude product were carried out as for 2.…”

“…[9,12] In both structures, the tert-butyl groups on the PϪN ring are bent towards the P 2 N 2 mean plane [for 3: C(1)ϪP 2 N 2 plane 161.05(3)°and C(5)ϪP 2 N 2 plane 170.94(3)°] and the orientation of the anilines gives an overall C 2v symmetry. The slight asymmetry of the P 2 N 2 ring in 3 is reflected by the PϪN endocyclic bond lengths, which vary from 1.707(3) to 1.728(3) Å .…”

“…In general, the coordination sphere of 11a resembles previously described structures for Ti, Zr and Hf complexes based on the cis-[(tBuNH)(PNtBu)] 2 ligand. [10,11,12] The cyclophosph()azane ring is almost planar and the phenyl rings are almost perpendicular to the P 2 N 2 plane and, hence, leave the metal center relatively open to nucleophilic attack.…”

“…[15,16] They have attracted most attention as precursors for hybrid (organic-inorganic) PϪN polymeric materials, [16c] and as ligand precursors for the synthesis of main group element compounds [9] and some, still rare, early transition metal complexes. [10,11,12] They preparation, in good yield, is commonly based on the reaction of cis- (ClPN-tBu) 2 (1) with either lithium amide or an excess of a free amine. [9] We investigated both of these methods to access the new, bulky bis(amino)cyclodiphosph()azanes.…”

Cyclodiphosphazanes with functionalities: Synthesis, reactivity and transition metal chemistry

“…The ever-growing interest in the chemistry of cyclodiphosphazanes or diazadiphosphetidines is due to the application of the planar saturated P 2 N 2 framework as building blocks to design a variety of cages, clusters and macrocycles with main group [1][2][3] or transition metal spacers [4][5][6] as well as their interesting coordination behavior both as neutral and anionic ligands [7][8][9][10]. Many of these complexes find application in homogeneous catalysis [11], polymerization of olefins [12], and in biological studies [13].…”