Cage Compounds of Heterotrimetallic Mixed Phosphanediide/Silanolate Aggregates with an Alkaline Earth Metal-Centered Phosphorus Octahedron

Abstract

The lithiation of potassium triisopropylsilylphosphanide yields the corresponding phosphanediide. The subsequent metathesis reaction with SrI(2) and BaI(2) in the presence of hexamethyldisiloxane gives hexalithium hexapotassium strontium hexakis(triisopropylsilylphosphanediide)bis(trimethylsilanolate) (1) and the corresponding barium derivative (2), respectively. The alkaline earth metal atoms are surrounded octahedrally by the phosphanediide ligands. Six P(3) faces of the octahedron are capped by the K atoms, and the P-P edges of two opposite P(3) faces are bridged by the lithium atoms. The Li cations are also bonded to the Me(3)SiO substituents giving a coordination number of three for the alkali metals.

Recent developments in the field of organic heterobimetallic compounds of the alkaline-earth metals

“…A heterotrimetallic complex is known for a trialkylsilylphosphanediide of the formula [K 6 Li 6 M II (PSiR 3 ) 6 (l 3 -OSiMe 3 ) 2 ] with M II = Sr and Ba. 62 The P 6 octahedron is centered by a strontium or barium atom (Fig. 4).…”

Low‐Valent Group 14 NHC‐Stabilized Phosphinidenide ate Complexes and NHC‐Stabilized K/P‐Clusters

“…Only some larger derivatives, mostly containing lithium,a re known in the literature. [38,40,[46][47][48][49][50][51][52][53][54][55][56][57] In contrast to compound 5,t he coordination number of the phosphorus atom in 6 increases to five. The potassium atoms coordinated by two phosphorus atoms (K1 and K1')h aveac oordination number of six (2 P, 2 O, 2 CH 3 agostici nteraction with the methyl groups of the tBu substituents), whereas the potassium atoms solely coordinated by one phosphorusa tom show one agostici nteraction to am ethyl group (K2, K2',K 3, and K3').…”

Chasing Multiple Bonding Interactions between Alkaline‐Earth Metals and Main‐Group Fragments

“…The respective synthesis involves the use of potassium phosphanide [K{PHSi(iPr) 3 }],a lkalineearth-metal iodides [AeI 2 ]( Ae = Sr,B a) and tert-butyllithium (tBuLi)i ns ilyl ether O(SiMe 3 ) 2 . [153] The reactive intermediate which leads to the second deprotonation of the phosphanide has not been isolated and one is tempted to draw comparisons to Lochmann-Schlosser bases (LICKOR bases). [154][155][156][157] The complex reaction mixture yielded Ae-centered ate-complexes of the composition [AeLi 6 K 6 {PSi(iPr) 3 } 6 (OSiMe 3 ) 2 ]( 42, Scheme 11), with the Me 3 SiO À ligandse merging from silyl ether cleavage.…”

“…Although heterometallic Ae–phosphandiide complexes are not covered by this Minireview, an interesting piece of work should be mentioned at this point since it nicely demonstrates another approach toward [Ae=E] moieties in general, and phosphandiides in particular. The respective synthesis involves the use of potassium phosphanide [K{PHSi( i Pr) 3 }], alkaline‐earth‐metal iodides [AeI 2 ] (Ae=Sr, Ba) and tert ‐butyllithium ( t BuLi) in silyl ether O(SiMe 3 ) 2 . The reactive intermediate which leads to the second deprotonation of the phosphanide has not been isolated and one is tempted to draw comparisons to Lochmann‐Schlosser bases (LICKOR bases) .…”