Synthesis and Characterization of a New Compound of Cobalt Ⅱ with Isonicotinamide and Evaluation of the Bactericidal Potential

In this work, the isonicotinamide was coordinated to the Cobalt ion in oxidation state +2. The relevance of this work is the investigation of the in vitro bactericidal potential of the synthesized complex when tested in Gram-positive and negative bacteria strains. This study is motivated by the need to obtain new materials that have antibiotic properties and that, in the future, may become an effective drug against resistant bacteria. A new coordination compound of Cobalt and isonicotinamide, [Co(H2O)(isn)3](BF4)2, was synthesized and described. The compound was characterized by thermoanalytical techniques TG-DTG and TG-DSC, where it was possible to propose the mechanism of thermal decomposition. Through the spectroscopy in the region of the medium infrared (FTIR), it is possible to infer the site of connection between isonicotinamide and metal. The bactericidal activity of [Co(H2O)(isn)3](BF4)2, CoCl2 and free Isonicotinamide were tested for the bacteria Streptococcus mutans (Gram+) and Escherichia coli (Gram−) and the synthesized compound showed to be sensitive for both bacteria.

Synthesis and Crystal Structure of One New Adduct of Isonicotinamide and 3,5-Dinitrosalicylic Acid

One new organic adduct,isonicotinamide·3,5-dinitrosalicylic acid with isonico-tin-amide（ina） and 3,5-dinitrosalicylic acid（3,5-dnsa） in 1：1 molar ratio,has been synthesized.Its struc-ture（C13H10N4O8,Mr = 350.25） was characterized by elemental analysis,IR and single-crystal X-ray diffraction analysis.The crystal belongs to the triclinic system,space group P1,with a = 8.812（4）,b = 9.487（5）,c = 9.604（6） ,α = 116.54（2）,β = 97.29（5）,γ = 98.35（4）°,V = 693.8（7） 3,Z = 2,Dc = 1.677 g/cm3,λ（MoKα） = 0.71073 ,μ = 0.142 mm-1,F（000） = 360,the final R = 0.0539 and wR = 0.1402 for 2417 unique reflections（Rint = 0.0288） with 1819 observed ones（Ⅰ 〉 2σ（Ⅰ））.Proton transfer reaction occurs between 3,5-dnsa and ina molecules,and the hydrogen bonds（N-H…O and C-H…O） with other interactions（π…π stacking and weak interactions of O…O and C…O） cooperatively construct a three-dimensional（3D） supramolecular structure.

Structural landscape investigations on bendable plastic crystals of isonicotinamide polymorphs

Three polymorphs(forms I,II and V)of isonicotinamide(INA)were mechanically flexible and exhibited one-dimensional(1 D)plasticity.Anisotropic intermolecular interactions contribute to the plasticity of single crystals:weak dispersive interactions between slip planes such as 1 D columns in forms I and II or 2 D layers in form V were stabilized by strong hydrogen bonds,allowing the layer or column's surface to glide smoothly without hindrance.The disparity of intermolecular interactions on plastic properties of INA polymorphic crystals was confirmed by energy framework analysis,nanoindentation tests and micro-Raman spectroscopy.The crystal which exhibits plastic property provides a promising application in pharmaceuticals and material sciences.