Highly Restricted Dimensionality in Cesium Aryl Phosphides

The molecular structures of four different crown ether adducts of CsP(H)tBu3Mes and CsP(H)Dmp (tBu3Mes =
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)tBu3Mes](18-crown-6)·0.5toluene (1·0.5toluene) in the monoclinic space group P21/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) Å3; Z = 8; Dcalcd = 1.247 g/cm3;
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 P212121. 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) Å3; Z = 4; Dcalcd = 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)(η2-C6D6)·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) Å3; Z = 8; Dcalcd = 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 P1̄. 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) Å3; Z = 1, Dcalcd = 1.321 g/cm3, 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.