Molecular Structures of the Heavier Alkali Metal Salts of Supermesitylphosphane:  A Systematic Investigation

Abstract

The molecular structures of the rubidium and cesium derivatives of supermesitylphosphane [i.e., (2,4,6-(t)Bu(3)C(6)H(2))PH(2) = (t)Bu(3)MesPH(2)] as well as several base adducts of these are reported. Sodium hydride, potassium hydride, rubidium metal, and cesium metal react with (t)Bu(3)MesPH(2) in tetrahydrofuran solution at room temperature to produce MPRH salts 1-4 [M = Na (1), K (2), Rb (3), Cs (4); R = (t)Bu(3)Mes] in good yields. X-ray-quality crystals of 2 and 3 were obtained by slow evaporation of solutions of the corresponding MP(H)(t)Bu(3)Mes species dissolved in toluene/thf. Complex 4 was crystallized from hot toluene. On the other hand, slow evaporation of a toluene/tetrahydrofuran solution of CsP(H)(t)Bu(3)Mes (4) produces crystals of the composition {[CsP(H)(t)Bu(3)Mes](2)(&mgr;-THF)(0.9).toluene}(x)() (5). Crystallization of 4 in the presence of pyridine yields crystals of {[CsP(H)(t)Bu(3)Mes](2)(&mgr;-pyridine)}(x)() (6). Also, crystallization of complexes 3 and 4 from toluene/N-methylimidazole (N-MeIm) gives the isomorphous complexes {[RbP(H)(t)Bu(3)Mes](2)(&mgr;-N-MeIm)}(x)() (7) and {[CsP(H)(t)Bu(3)Mes](2)(&mgr;-N-MeIm)}(x)() (8), respectively. However, crystallization of 4 from toluene in the presence of bidentate or polydentate bases such as dimethoxyethane or pentamethyldiethylenetriamine does not result in incorporation of these bases into the lattice. Instead, the toluene solvate {[CsP(H)(t)Bu(3)Mes](2)(eta(3)-toluene)(0.5)}(x)() (9) is obtained. On the other hand, crystallization of 4 from toluene/ethylenediamine gives the base adduct {[CsP(H)(t)Bu(3)Mes](2)(&mgr;-ethylenediamine)}(x)() (10). Complex 3 crystallizes in the triclinic space group P&onemacr;. Crystal data for 3 at 218 K: a = 6.71320(10) Å, b = 10.5022(2) Å, c = 14.9733(3) Å, alpha = 91.3524(13) degrees, beta = 102.5584(13) degrees, gamma = 107.7966(14) degrees; Z = 1; R(1) = 6.55%. Complex 4 crystallizes in the triclinic space group P&onemacr;. Crystal data for 4 at 223 K: a = 7.0730(14) Å; b = 10.395(2) Å; c = 14.933(2) Å; alpha = 81.97(1) degrees; beta = 76.35(2) degrees; gamma = 71.824(14) degrees; Z = 1; R(1) = 4.56%. Complex 5 crystallizes in the monoclinic space group P2(1)/c. Crystal data for 5 at 243 K: a = 15.039(2) Å; b = 16.152(3) Å; c = 20.967(5) Å; beta = 91.53(2) degrees; Z = 4; R(1) = 4.83%. Complex 6 crystallizes in the orthorhombic space group Pbcn. Crystal data for 6 at 298 K: a = 14.686(2) Å; b = 21.295(5) Å; c = 28.767(5) Å; Z = 8; R(1) = 5.61%. Complex 7 crystallizes in the orthorhombic space group Pbcn. Crystal data for 7 at 218 K: a = 14.5533(2) Å; b = 21.4258(5) Å; c = 28.5990(5) Å; Z = 8; R(1) = 4.61%. Complex 8 crystallizes in the orthorhombic space group Pbcn. Crystal data for 8 at 219 K: a = 14.6162(2) Å; b = 21.3992(3) Å; c = 28.7037(2) Å; Z = 8; R(1) = 3.57%. Complex 9 crystallizes in the triclinic space group P&onemacr;. Crystal data for 9 at 293 K: a = 11.147(4) Å; b = 14.615(4) Å; c = 14.806(5) Å; alpha = 70.57(3) degrees; beta = 71.85(3) degrees; gamma = 72.93(2) degrees; Z = 2; R(1) = 5.13%....

Di(benzothiazol‐2‐yl)phosphanide as a Janus‐Head Ligand to Caesium

“…The P À Cs bond lengths of 384.7(2) and 406.9(3) pm in two otherwise almost identical molecules vary by 20 pm. [28] The NÀCs bond lengths are 321.4(4) and 318.6(3) pm. In polymeric [(Cs 2 A C H T U N G T R E N N U N G (m-thf){Ph-A C H T U N G T R E N N U N G (Me 3 SiN)P} 2 ) n ] a similar bonding situation with two m-bridging Cs cations across N···N is present and the N À Cs bond lengths range from 309.5(4) to 316.2(4) pm.…”

“…This is at the long end of the published range. [28] Only a few S···Cs distances are listed. Thiolato complexes show the shortest distances from approximately 330 to 360 pm.…”

Syntheses and Molecular Structures of Novel Alkali Metal Tetraorganylcyclopentaphosphanides and Tetraorganyltetraphosphane‐1,4‐diides

“…This is a rare situation, [23] and has only been observed twice in the structures of alkali metal phosphanides. [24] Bridging THF molecules were also observed in the molecular structure of the tetrameric sodium and potassium fluorenone ketyls [Na 4 (OC 13 [23] The PϪP bond lengths, which range from 216.6(1)Ϫ 226.2(2) pm, are in the typical range for single bond lengths. [25] In spite of these general similarities, there are significant differences between the coordination modes of Na and K. Whereas for 4 and 6 the phosphorus alkali metal distances are in the typical range for related sodium and potassium phosphanides [9] both for the internal and terminal phosphorus atoms of the chain Figure 5).…”

Heterometallic transition metal clusters and cluster-supported coordination polymers derived from Tp- and Tp*-based Mo(W) sulfido precursors

“…Each N atom from bipy was found to bridge two Cu atoms from the same cluster core. This bipy is therefore coordinated in a 4 -N fashion with four Cu atoms from the two cluster cores, which is, to our knowledge, unprecedented for bipy, though the N atoms from some other pyridine derivatives are occasionally found in a 2 -N coordination mode [93][94][95]. The formation of such a rare coordination mode is probably due to the association of the two CN bridges with the two Cu centers in the butterfly-shaped [Tp*WS 3 Cu 2 ] core which sterically 'squeezes' the bipy ligand to form such a 4 -coordination with the Cu-N bond distances of 2.416(6)Å and 2.574(6)Å, respectively.…”