The deprotonation-substitution reactions of both the cis and trans isomers of nongeminally substituted [(Me)(Ph)P=N](3) were investigated. Treatment of the trans isomer, 1, with 3 equiv of n-BuLi followed by 3 equiv of Mel gave only nongeminal trans-[(Et)(Ph)P=N](3) 3, while the same reaction sequence on cis-[(Me)(Ph)P=N](3), 2, gave a mixture of nongeminal di- and trisubstitution products, cis-Et2MePh3P3N3, 4, and cis-Et3Ph3P3N3, 5. These trimers were separated by column chromatography. No changes in the stereochemistry of the rings occurred during these reactions. Compound 4 was also prepared using 2 equiv of the reactants and was then converted to 5 by treatment with a single equivalent of BuLi and Mel. Thermal analysis of the new cyclic trimers indicates that ring-opening polymerization does not occur and that sublimation occurs at ca. 300 degreesC. The structures of 4 and 5, obtained by X-ray diffraction, illustrate the basketlike shape of these molecules with an aromatic bowl formed by the phenyl rings on the top rim, while the structure of 3 clearly shows the trans orientation of the substituents. Crystal data for trans-Et3Ph3P3N3, 3, at 20 degreesC are as follows: C24H30N3P3 monoclinic, a = 14.273(2) Angstrom, b = 9.370(2) Angstrom, c = 19,600(3) Angstrom. beta = 107.16(1)degrees, P2(1/n), Z = 4. Crystal data for cis-Et2MePh3P3N3, 4, at 20 degreesC are as follows: C23H28N3P3, triclinic, a = 10.276(2) Angstrom, b = 10.699(2) Angstrom, c = 11.925(2) Angstrom, alpha = 72.07(2)degrees, beta = 73.79(1)degrees, gamma = 85.87(1)degrees, P1, Z = 2, Crystal data for cis-Et3Ph3P3N3, 5, at 20 degreesC are as follows: C24H30N3P3 monoclinic, a = 29.488(2) Angstrom, b = 9,8391(1) Angstrom, c = 21,172(2) Angstrom, beta = 126.30(1)degrees, C2/c, Z = 8.