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Two new supramolecular synthon induced single crystals of metal-orotato complexes of formula [Cu(Orotate)·2H 2 O] 2 ( 1 ), [Mn(Orotate) 2 ·2H 2 O]·2H 2 O] ( 2 ), have been engineered and synthesized by self-assembly of metal salts with orotic acid in presence of 25% ammonia solution. Although both complexes crystallize in similar crystal system and different coordination geometries [(square planar ( 1 ), octahedral ( 2 )] but identical synthon patterns recur after complex formation. N H⋯O, O H⋯O synthons were the only artifact for both the hydrogen bonded metal–organic architecture. X-ray structural analysis, EPR, temperature independent paramagnetism (TIP) analysis, have been discussed. DFT calculation is used to rationalize the magnetic behavior of both the complexes. These calculations underline the pathway of magnetic exchange interactions through N H⋯O, O H⋯O supramolecular synthons and confirm, that the magnetic interactions propagate through such contacts in complex 1 and 2 . [ABSTRACT FROM AUTHOR]

The synthesis and characterization of new supramolecular networks based on mixed ligands as orotate with 1,3-di(4-pyridyl)propane or malonic acid are reported. Both coordination polymers was characterized using X-ray crystallography, magnetic measurements, electron paramagnetic resonance, and density functional theory calculations. The significant role of hydrogen bonding O H⋯O and N H⋯O in formation of 2D coordination network and magnetic exchange pathway was found. [Display omitted] Two new coordination network based on mixed ligands, orotic acid potassium salt with 1,3-Di(4-pyridyl)propane (dpp) and malonic acid at room temperature were synthesized as [Cu 2 (dpp)(HOr) 2 ·2H 2 O]n (1) and [Cu(HOr)(H 2 O) 2 ]n (2) respectively. To strategically design and synthesize Cu(II)-coordination networks where N H⋯O and O H⋯O hydrogen bonds act as connecting tools in the construction of three dimensional networks have been discussed. The both complexes have been characterized by single crystal X-ray analysis, elemental analysis, magneto-structural study along with EPR study. The magnetic data reveals that the complex 1 shows antiferromagnetic exchange interactions while complex 2 shows ferromagnetic exchange interaction through {⋯H N C O} dimer. The DFT calculation and HOMO/LUMO molecular orbitals analysis is used to rationalized the magnetic behavior in these coordination polymers. [ABSTRACT FROM AUTHOR]

• Magneto-structural analyses of two coordination polymers based on Orotic acid are well explored. • Cu-orotate is first anionic, orotate based coordination polymer exhibit weak ferromagnetic behavior. • Ni-orotate coordination polymer becomes evidence for weak antiferromagnetic behavior. • DFT calculation underline the pathway of magnetic exchange interactions through N—H⋯O, O—H⋯O supramolecular synthons and confirm that the magnetic interactions propagate through such contacts in complex 1 and 2. Orotato based coordination network of formula [Cu(HOr) 2 2−. 2(CH 3) 2 ―NH 2 + n (1), and [Ni(HOr) . 3H 2 O] n (2), have been synthesized hydrothermally by self-assembly of orotic acid (H 3 Or) with metal salts Cu(OAc) 2 . H 2 O and Ni(NO 3) 2 • 6H 2 O respectively. Single crystal X-ray study confirms that in 1 electroneutrality is obtained with a compensating cation i.e. (CH 3) 2 ‒NH 2 + and trans-trans μ2η1:η1 bridging carboxylate extend the Cu-Orotate moiety into 2D coordination network showing square lattice topology (sql) which through { ... H‒N‒C = O} dimer yields into 3D hydrogen bonded coordination polymer.Temperature dependent measurements of magnetic susceptibility reveals the occurrence of competitive exchange interactions with weak ferromagnetic character in 1 (J = +0.31 cm–1) and weak antiferromagnetic interaction in 2 (J = - 0.52 cm–1). The dominantzero – field splitting effect is observed in Ni(II) ion. Two important magneticsuper exchange pathway transmitted through carboxylate oxygen of ligand through N‒H ... O, and O‒H ... O supramolecular synthons along with long Cu•••Cu separation of 6.635 Å (1) or Ni•••Ni separation of 7.700 Å (2). The DFT calculation analysis is used to rationalized the magnetic behavior in these coordination polymers. Image, graphical abstract [ABSTRACT FROM AUTHOR]