Coordination Behavior of Chelidamic Acid With V^V, Ni^II, Fe^III, and Ca^II: Syntheses, X‐ray Characterization and DFT Studies

Abstract

Four new complexes of chelidamic acid (H3cda) in the presence\ud of 2-aminopyrimidine (apym) or 2,4,6-triamino-1,3,5-triazine\ud (tata) as external ligands, namely (apymH)[VO2(Hcda)]·H2O (1),\ud [Ni(Hcda)(apym)(H2O)2]·H2O (2), (apymH)[Fe(Hcda)2] (3), and (tataH)\ud 2(tata)2[Ca2(cda)2(H2O)6]·H2O (4) were synthesized. X-ray diffraction\ud analysis of 1-4 revealed the formation of 3D frameworks\ud generally involving weak interactions (mainly H-bonds)\ud between metal complexes of chelidamic acid, protonated or\ud deprotonated external ligands apym or tata and co-crystallized\ud water molecules. Some complexes present remarkable assemblies\ud in the solid state governed by unconventional noncovalent\ud interactions that have been analyzed by means of DFT\ud calculations. Solution studies were also performed to fully characterize\ud the new compounds

Relationship between Antioxidant Activity and Ligand Basicity in the Dipicolinate Series of Oxovanadium(IV) and Dioxovanadium(V) Complexes

“…Single-crystal XRD measurements show that [VOO(dipic)](2-phepyH)•H 2 O crystallize in the monoclinic P2 1 /c space group with one 2-phenylpyridinium cation, one dioxo-(pyridine-2,6-dicarboxylato)-vanadium(V) anion and one water molecule in the asymmetric unit (Figure 1, Table 1). The bond lengths and angles characterizing the geometry of the dioxo-(pyridine-2,6-dicarboxylato)-vanadium(V) cation are similar to those observed in the other crystal structures containing this ion [23,24] 2). The neighbouring blocks are linked via π-π interactions between 2-phenylpyridinium cations to form a 3D framework structure.…”

Effects of N-oxidation on the molecular and crystal structures and properties of isocinchomeronic acid, its metal complexes and their supramolecular architectures: experimental, CSD survey, solution and theoretical approaches

“…A search of the CSD (version 5.38, with updates until February 2017) for the pydco ligand returned no published examples of transition metal complexes coordinated to this ligand. Previously in our group we have synthesized a series of complexes with N/O donor ligand H 2 pydc [62][63][64][65] and here we report the corresponding transition metal complexes with exclusively Odonor H 2 pydco ligand. The aim was to explore how altering the coordination mode of the ligand changes the molecular structures, non-covalent interactions and therefore the supramolecular structures of these complexes.…”

Influence of 2-Amino-4-methylpyridine and 2-Aminopyrimidine Ligands on the Malonic Acid-Cu(II) System: Insights through Supramolecular Interactions and Photoresponse Properties

“…The realm of transition metal complexes is considered to take up one of the forefront positions in the traditional field of chemistry and considered to cover almost all the relevant topics from structural to functional point of view. This extensive field of chemistry using transition metals and organic ligands as building blocks is enriched with high design ability and diversity of architectural motifs. − These complexes are capable of forming polymeric chains through coordination bonds; − besides, they can also produce supramolecular polymers via weaker noncovalent interactions such as hydrogen bonding, lp···π, π···π stacking, π···cation, and π···anion interactions. − A preferred combination of these weak interactions along with covalent bonds form a supramolecular building block that takes an active participation in the field of drug delivery, gas storage, separation, barrier diode, sensing, and catalysis. − Some specific noncovalent interactions involving aromatic systems such as π···π and salt bridge···π have immense influence in various chemical and biological processes as well. , Again, inclusion of additional aromatic N-donor auxiliary ligands in transition metal complexes creates diversity to the existing supramolecular structures as these N-donor ligands can participate in hydrogen bonding and π-ring containing weak interactions as well as coordinate to the metal. − …”