2,12-Dichloro-10,20-diphenyl-5,7,15,17-tetrahydro-6H,16H-dibenzo[d,l][1,9,2,6,10,14]dioxotetraazacyclohexadecine-6,16-dione dioxane solvate as a potential macrocyclic hexadentate ligand.

The macrocyclic title compound crystallizes as a dioxane solvate, C(30)H(22)Cl(2)N(4)O(4) x C(4)H(8)O(2), with two independent formula units in the unit cell. The observed syn conformation is controlled by both intramolecular N-H...O hydrogen bonds and intermolecular C-H...pi interactions. The relative macrocyclic inner bore is estimated to be 4.19 Angstrom. In the crystal structure, molecules form dimers via intermolecular C-H...pi interactions, and these dimers are, in turn, linked to form columns along the a axis by intermolecular C-H...O hydrogen bonds. Both X-ray diffraction analysis and density functional theory (DFT) calculations reveal that the macrocycle possesses very high flexibility. This property, as well as the presence of six donor atoms accessible for coordination, makes the title macrocycle a very promising ligand for complexation with the majority of transition metals.

Chloridobis[(2-oxoazocan-1-yl)methyl]germanium(IV) trifluoromethanesulfonate.

In the title compound, [Ge(C(8)H(14)NO)(2)Cl]CF(3)SO(3), which is the first complex containing an eight-membered lactam (enantholactam) as ligand, the coordination polyhedron of the Ge(IV) atom is intermediate between trigonal-bipyramidal and square-pyramidal. Quantum chemical calculations of the crystal structure indicate the absence of additional coordination bonding between the Ge(IV) atom and the trifluoromethanesulfonate anion.

Two germatranes with bulky substituents.

In 1-adamantyl-2,8,9-trioxa-5-aza-1-germabicyclo[3.3.3]undecane or 1-adamantylgermatrane, [Ge(C(10)H(15))(C(6)H(12)NO(3))], (I), and (2,8,9-trioxa-5-aza-1-germabicyclo[3.3.3]undecan-1-yl)methyl N-cyclohexylcarbamate or [(germatran-1-yl)methyl] N-cyclohexylcarbamate, [Ge(C(6)H(12)NO(3))(C(8)H(14)NO(2))], (II), the Ge atoms are characterized by trigonal-bypiramidal configurations. The Ge...N distances [2.266 (3) and 2.206 (3) A in (I) and (II), respectively] are among the longest observed in germatranes. The significant distortion of the apical N-Ge-C angle in (II) is caused by crystal packing effects.