Crystal structure of bis{aqua[μ-2-(2-carboxylatophenyl)acetato- κ3O1:O3,O4](1,10-phenanthroline-κ2N,N')manganese(II)}, [Mn(C9H6O4)(C12H8N2)(H2O)]2

Abstract

Source of materialThem ixture of 2-(2-carboxyphenyl)acetic acid (homophthalic acid =H 2 hmph,0 .1 mmol,0 .0181g ), 1,10-phenanthroline hydrate (0.1m mol, 0.01980 g), Mn(OAc) 2 × 4H 2 O( 0.1 mmol, 0.0243 g), NaOH (0.1m mol, 0.0393 g) and H 2 O( 8m l) was placed in aTeflon-lined stainless-steel vessel, heated to 393 Kfor 3d ays, and then slowly cooled down to room temperature for crystallization. Pink block-shaped crystals of the title compound were obtained. DiscussionDesign and construction of supramolecular coordination polymeric networks depending upon hydrogen bonding and/or p-p stacking interactions is of great interest due to the enormous variety of intriguing structural topologies and the potential use of these materials as functional materials [1][2][3]. It is well known that flexible aromatic multi-carboxylate ligands play acrucial role in creating desirable frameworks, and that N-containing auxiliary ligands can modify the structures and properties of the resulting metal-organic complexes [4][5][6]. With these considerations in mind, we have chosen the homophthalic acid (H 2 hmph) as a bridging ligand to construct new coordination complexes. The asymmetric unit of the title crystal structure contains one manganese cation, aphen, ahmph 2-and one coordinating water molecule. In this complex, manganese atom is six-coordinated in adistorted octahedral manner (MnN 2 O 4 )bytwo Natoms from a chelating phen ligand, three oxygen atomsfrom two hmph anions and one coordinating water molecule, with respective bond lengths of 2.238(2), 2.259(2) and 2.102(2)-2.272(2) Å. The adjacent Mn atomsa re separated by two hmph anion connectors to form adinuclearbuilding unit with aMn×××Mn separation within the binuclear unit equal to 6.6338(9) Å. Each dinuclear building unit interacts with another two by hydrogen bonding of the coordinating water and one of acetato oxygen atoms (d(O5×××O4) =2 .660(3) Åa nd ÐO-H×××O=1 70.3°), forming a one-dimensional double-chain along [010].The hydrogen bonds between uncoordinating oxygen atom of the -COO-group and coordinating water molecule (d(O5×××O2#) =2 .665(3) Å, ÐO-H×××O=150.1°) are also present in the chain. Weaker p-p interactions are observed between the phen ligands of the two adjacent chains,forming alayer structure. Individual layers are entirely cohered together by relatively weak van der Waals interactionstoforma3Dsupramolecularnetwork. Thestructure of the title complex is isostructural with the previously reported [M 2 (hmph) 2 (phen) 2 (H 2 O) 2 ](M =Zn,Co,Ni) [7][8][9][10], showing that metal(II)ions may not have asignificant effect on the assembly of the coordination networks.