Crystal and molecular structure of the macrocyclic nickel(II) complex [Ni(C18H14N4)]: dibenzo[b,i][1,4,8,11]tetraaza[14]annulenenickel(II)

Characterizations and X-ray Crystal Structure of Asymmetrical 2,4,9,11-Tetramethyl-1,5,8,12-monobenzotetraazacyclo[14]annulene Palladium(II) Complex

“…Crystal data and refinement parameters and the selected bond distances and angles were presented in Tables 1 and 2, respectively. The average of four Pd-N bond distances was 1.970 Å that is longer than the corresponding Ni-N distances (1.870 Å) for symmetrical nickel(II) complex 28 but shorter than Pd-N distances (1.996 Å) for symmetrical palladium complex 18 owing to different basicity for phenylenediamine and ethylenediamine. Such difference of bond distances might be attributed to the larger ionic radius of palladium.…”

Influence of Introduced Substituents on the Anion-selectivity of [14]Tetraazaannulene Complexes

“…It is known that dibenzotetraaza [14]annulene nickel complexes without any substituents on the azaannulene framework have planar structures. 44 On the other hand, dibenzotetraaza [14]annulene nickel complexes with substituents on the C atom adjacent to the N atom of the azaannulene framework have saddle-shaped structures due to their steric interactions with the ortho aromatic hydrogens of the two benzene rings. 31,45,46 Hence, the obtained computational results seem to be reasonable.…”

High-Z′ and twinning behavior in 3,4-dinitrobenzoic acid

“…3,4-Dinitro-substituted benzoic acids are important precursors for the production of peripherally substituted metallotetraaza [14]annulenes (MTAAs). MTAAs are porphyrin analogs with either a planar or saddle-shaped geometry, depending on the substituents placed on the diiminato framework of the molecule (Weiss et al, 1976(Weiss et al, , 1977Ricciardi et al, 1995;Mandon et al, 1987;Wooodruff et al, 1976). MTAAs have been extensively studied because when partially oxidized they become electronically conducting materials, while in their reduced forms they are electronic insulators.…”