The molecular structures of terphenyl derivatives of trivalent ytterbium, thulium, and yttrium of general composition DnpLnCl(2)(THF)(2) [Dnp = 2,6-di(1-naphthyl)phenyl] are reported. The complexes (Ln = Yb: 1: Ln = Tm: 2; Ln = Y: 3) are synthesized by reaction of 1 equiv of DnpLi with 1 equiv of LnCl(3) (Ln = Yb, Tm, or Y) in tetrahydrofuran at room temperature in 50% yield. Attempts to prepare a Dnp scandium compound gave heterobimetallic [(THF)(3)Sc2OCL5Li(THF)](2) (4) in low yield. 1 crystallizes in the monoclinic space group C2/c. Crystal data for 1 at 203 K: a = 14.333(3) Angstrom, b = 16.353(3) Angstrom, c = 12.427(2) Angstrom, beta = 91.021(4)degrees, Z = 4, D-calcd = 1.637 g cm(-3), R-1 = 4.44%. 2 crystallizes in the monoclinic space group C2/c. Crystal data for 2 at 203 K: a = 14.333(1) Angstrom, b = 16.374(2) Angstrom, c = 12.404(1) Angstrom, beta = 90.934(2)degrees, Z = 4, D-calcd - 1.628 g cm(-3), R-1 = 3.00%. 3 crystallizes in the monoclinic space group C2/c. Crystal data for 3 at 203 K: a = 14.348(3) Angstrom, b = 16.476(3) Angstrom, c 12.356(2) Angstrom, beta = 90.987(4)degrees, Z = 4, D-calcd = 1.441 g cm(-3), R-1 = 5.62%. 4 crystallizes in the monoclinic space group P2(1)/n. Crystal data for 4 at 203 K: a = 11.0975(9) Angstrom, b = 11.0976(9) Angstrom, c = 21.3305(18) Angstrom, beta = 94.718(2)degrees, Z = 2, D-calcd = 1.051 g cm(-3), R-1 = 3.45%. Complexes 1-3 represent examples of novel chiral (racemic) organometallic complexes of the lanthanide elements ytterbium and thulium and the group 3 element yttrium, respectively. The molecular structures of monomeric 1-3 exhibit distorted trigonal-bipyramidal coordination environments at the metal center, with the two oxygen atoms of the tetrahydrofuran ligands occupying the axial positions of a trigonal-bipyramidal coordination polyeder. The molecular structure of the scandium compound 4 shows a complex polynuclear heterobimetallic arrangement.