Solid state stereochemistry of crown ethers: X-ray crystal structure and 13C NMR studies of the LiNCS complex of 1,4,7,11-tetraoxacyclotetradecane

The title complex is asymmetric in the crystal due to the spatial orientation of the NCS function. The space group has been determined to be P2 1 with a = 9.496(3), b = 8.736(3), c = 9.676(3) Å, = 117.859(5)°, and Z = 2. The solid state 13 C NMR spectrum is consistent with the lack of symmetry in the crystal and there is little evidence for large amplitude motion in the macrocycle as determined from the dipolar dephased spectrum.Key words: macrocyclic crown ether, lithium complex.