X-Ray Structures of Three Polymeric and Two Mononuclear Metal Complexes on the Base of p-Aminobenzoic Acid

• Published in: Journal of chemical crystallography 2016-09, Vol.46 (8-9), p.352-363
• Main Authors: Ibragimov, Aziz B., Ashurov, Jamshid M., Zakirov, Bakhtiyar S.
• Format: Article
• Language: English
• Subjects: Chemistry; Chemistry and Materials Science; Coordination compounds; Coordination polymers; Crystallography; Crystallography and Scattering Methods; Diethanolamine; Hexagons; Inorganic Chemistry; Organometallic Chemistry; Original Paper; Physical Chemistry; Polymers
• ISSN: 1074-1542; 1572-8854
• DOI: 10.1007/s10870-016-0665-8

Crystals of five coordination compounds have been grown from solutions containing p -aminobenzoic acid (PABA), diethanolamine (DEA) and salt of the definite metal. The X-ray crystallography attests that complexes [Co(PABA) 2 (H 2 O) 2 ] n ·H 2 O ( 1 ), [Ni(PABA) 2 (H 2 O) 2 ] n ·H 2 O ( 1′ ) and [Zn(PABA) 2 (H 2 O)] n ·H 2 O ( 2 ) are polymeric, while Mn(DEA) 2 ·2(PABA)·2(H 2 O) ( 3 ) and Cr(DEA) 2 ·2(PABA) ( 4 ) are mononuclear coordination compounds. In the isomorphic polymers 1 and 1′ metal ions are bridged to infinite columns by coordination bonds of the two antiparallel PABA molecules (bimolecular association). The complex 2 is 2-D polymer repeating units of which are hexagons generated by combination of mono- and bimolecular associations. All six coordination sites of Mn 2+ - and Cr 2+ -ions in 3 and 4 are occupied by two DEA molecules retaining PABA anions in outer sphere. The CSD analysis shows that there are five types of coordination polymers bridged by O and N atoms of the PABA-molecules. As a result of this research two new type motif polymers have been added to the existing list. Graphical Abstract