Highly Restricted Dimensionality in Cesium Aryl Phosphides

The molecular structures of four different crown ether adducts of CsP(H) t Bu 3 Mes and CsP(H)Dmp ( t Bu 3 Mes = 2,4,6-tri- tert -butylphenyl; Dmp = 2,6-dimesitylphenyl) are reported featuring monomeric or triple-decker-type structures in the solid state. The crown ether adducts 1, 2, and 4 are prepared in good yields using different stoichiometries CsP(H)R/18-crown-6 followed by crystallization of the corresponding cesium phosphide derivative from toluene at −30 °C. 1 crystallizes from toluene as the crown ether adduct [CsP(H) t Bu 3 Mes](18-crown-6)·0.5toluene ( 1 ·0.5toluene) in the monoclinic space group P 2 1 / c . Crystal data for 1 ·0.5toluene at 243 K: a = 22.919(4) Å; b = 17.184(3) Å; c = 21.307(6) Å; β = 113.79(2)°; V = 7697(4) Å 3; Z = 8; D calcd = 1.247 g/cm 3; R1 = 4.89%. 2 crystallizes from toluene in the presence of excess crown ether as the adduct [CsP(H)Dmp](18-crown-6) ( 2 ) in the orthorhombic space group P 2 1 2 1 2 1 . Crystal data for 2 at 173 K: a = 13.8223(2) Å; b = 14.6926(2) Å; c = 18.6259(2) Å; V = 3782.60(8) Å 3; Z = 4; D calcd = 1.304 g cm - 3; R1 = 3.97%. Using deuterated benzene instead of toluene as the recrystallization solvent, 2 crystallizes as the benzene solvate [CsP(H)Dmp](18-crown-6)(η 2 -C 6 D 6 )·benzene ( 3 ·benzene) in the orthorhombic space group Pccn (No. 56). Crystal data for 3 at 173 K: a = 20.1567(4) Å; b = 25.8617(5) Å; c = 17.3173(4) Å; V = 9027.3(5) Å 3; Z = 8; D calcd = 1.340 g cm - 3; R1 = 9.34%. 4 crystallizes from toluene using a 2:1 stoichiometry [CsP(H)Dmp:18-crown-6] as the crown ether adduct [CsP(H)Dmp] 2 (18-crown-6)·toluene ( 4 ·toluene) in the triclinic space group P 1̄. Crystal data for 4 ·toluene at 198 K: a = 11.2885(2) Å; b = 11.6675(2) Å; c = 14.5247(2) Å; α = 66.5752(3)°; β = 71.1301(7)°; γ = 88.0975(8)°; V = 1650.96(6) Å 3; Z = 1, D calcd = 1.321 g/cm 3, R1 = 4.29%. 1 ·0.5toluene, 2, and 3 ·benzene represent first examples of monomeric cesium phosphide species, while the solid state structure of 4 ·toluene features a triple-decker-type arrangement.