A new supramolecular coordination compound of Mg(II) with chelidamic acid: Synthesis, spectroscopic, crystal structures, and thermal analysis (original) (raw)
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The Journal of Physical Chemistry B, 2010
Two Mg(II) malonate complexes with protonated 2-aminopyridine and protonated 2-amino-4-picoline as counterions, namely, (C 5 H 7 N 2) 4 [Mg(C 3 H 2 O 4) 2 (H 2 O) 2 ](ClO 4) 2 (1) and (C 6 H 8 N 2 H) 2 [Mg(C 3 H 2 O 4) 2 (H 2 O) 2 ] • 4H 2 O (2) [C 5 H 7 N 2) protonated 2-aminopyridine, C 3 H 4 O 4) malonic acid, C 6 H 8 N 2 H) protonated 2-amino-4picoline], have been synthesized from purely aqueous media, and their crystal structures have been determined by single-crystal X-ray diffraction. The role of lone pair • • • π interactions in stabilizing the self-assembly process appears to be of great importance in both complexes. Additional weak forces like anion • • • π and noncovalent O • • • O interactions are also found to be operating in 1. A rare combination of lone pair • • • π and anion • • • π interactions in 1, of the type lone pair • • • π/π • • • π/π • • • anion • • • π/π • • • lone pair, is observed, and this unusual supramolecular network is fully described here. An attempt to prepare an analogous complex with 2-amino-4-picoline resulted in 2, which is isomorphous with our recently reported transition-metal complexes of the type (C 6 H 8 N 2 H) 2 [M(C 3 H 2 O 4) 2 (H 2 O) 2 ] • 4H 2 O (M) Ni/Co/Mn). A high-level DFT-D study (RI-B97-D/TZVP) has been used to characterize the different noncovalent interactions present in the solid state. We have also analyzed some crystal fragments to examine energetically some important assemblies that drive the crystal packing. Finally, we have studied the influence of magnesium on some hydrogenbonding interactions.
Bis2-(dimethylamino-κN)-α,α-diphenylbenzenemethanolato-κOmagnesium(II)
IUCrData
The title magnesium complex, [Mg(C21H20NO2)2(C4H8O)] n , exhibits two N,O-bidentate 2-(dimethylamino)-α,α-diphenylbenzenemethanolate ligands, forming two six-membered chelate rings. The distorted square-pyramidal coordination sphere of the MgII atom is completed by the O atom of a tetrahydrofuran ligand, with its O atom in the apical position. The O and N atoms are in a mutual trans arrangement. Except for two C—H...π interactions, no significant intermolecular interactions are observed in the crystal.
mer- Triaqua(1,10-phenanthroline-κ 2 N , N ′)(sulfato-κ O )magnesium(II)
Acta Crystallographica Section E Structure Reports Online, 2008
Phenanthroline (phen) is one of the most commonly used aromatic N,N' chelating ligands and has in form of several functionalized derivatives been widely used in the construction of supramolecular architectures. Copper(II), zinc(II) and cadmium(II) derivatives of phen have been reported (Xu et al., 2003; Zhang et al. 1999). As a continuation of these studies, we now report the crystal structure of the title complex, (I). As illustrated in Fig. 1, the Mg(II) ion is surrounded by two N atoms from the phen ligand and four O atoms from three meridionally arranged H 2 O molecules and one sulfato group to form distorted MgN 2 O 4 octahedron. The Mg-O and Mg-N bond lengths are in the noramal range of 2.033 (1)-2.086 (1) and 2.210 (1)-2.234 (2) Å, respectively. The units are connected by O-H•••O hydrogen bonds to produce a complex three dimensional supramolecular network, shown in figure 2. Experimental 1,10-phenanthroline (0.05 g, 0.25 mmol) was dissolved in a water-DMF mixture (1:1 v/v, 50 ml), and MgSO 4 × 7 H 2 O (0.06 g, 0.25 mmol) was added to the solution. The resulting mixture was stirred at room temperature for 12 h and filtered. Colorless single crystals of (I) were obtained from the solution after several weeks. Refinement The carbon-bound H atoms were positioned geometrically (C-H = 0.93-0.97 Å) and refined as riding with U iso (H) = 1.2U eq (C). The O-bound H atoms were located in a difference map and refined with a distance restraint of 0.85 (1) Å and the constraint U iso (H) = 1.5U eq (O).
Synthesis, spectroscopy and supramolecular structures of two magnesium 4-nitrobenzoate complexes
Journal of Chemical Sciences, 2007
The aqueous reaction of [Mg(H 2 O) 6 ]Cl 2 with the in situ generated sodium salt of 4-nitrobenzoic acid (4-nbaH) and N-methylimidazole (N-MeIm) results in the formation of the dinuclear complex [Mg(H 2 O)(N-MeIm) 2 (4-nba) 2 ] 2 1 (4-nba = 4-nitro benzoate), while the direct reaction of [Mg(H 2 O) 6 ]Cl 2 with sodium 4-nba leads to the formation of the mononuclear complex, [Mg(H 2 O) 6 ](4-nba) 2 ⋅2H 2 O 2. In the centrosymmetric dimer 1, each Mg atom is coordinated to an aquo ligand, two monodentate N-MeIm ligands and a monodentate 4-nba ligand. The second 4-nba ligand functions as a bridging bidentate ligand, linking the metal centers and completes the hexacoordination around each Mg(II). The dimeric molecules of 1 are linked into a one-dimensional chain along b with the aid of intra-as well as intermolecular H-bonding interactions between the coordinated water and the free oxygen atom of the monodentate 4-nba ligand. In the mononuclear complex [Mg(H 2 O) 6 ](4-nba) 2 ⋅2H 2 O 2, the Mg(II) is located on an inversion center and its structure consists of an octahedral [Mg(H 2 O) 6 ] 2+ dication, a free uncoordinated 4nba anion and a lattice water molecule. One of the H atoms attached of the lattice water is disordered over two positions. The hexaaquomagnesium(II) dication, the 4-nba anion and the lattice water molecule are linked by intra-and intermolecular H-bonding interactions resulting in the formation of alternating layers of [Mg(H 2 O) 6 ] 2+ dications and 4-nba anions in the crystallographic bc plane. The lattice water molecules are situated between the cations, while the 4-nba anions are arranged antiparallel to each other along b.
Journal of Molecular Structure, 2011
Two mixed-ligand Ag(I) coordination polymers (CPs), [(NH 4 )Ag 3 (MA) 2 (suc) 2 ] n (1), [Ag 2 (MA) 2 (adip)Á-CH 3 OHÁH 2 O] n (2), (where MA = melamine, H 2 suc = succinic acid, H 2 adip = adipic acid) have been synthesized and structurally characterized by element analysis, IR and X-ray single-crystal diffraction. The CP 1 is a three-dimensional (3D) framework in which the MA acts as a tridentate ligand and suc 2À anion shows three types of coordination modes. Each Ag(I) ion acts as a 4-connected node to generate three-and sixmembered cycles, as a result, the network can be simplified to be an overall multi-layered Kagomé topology. The CP 2 is a 2D single-layer structure constructed by tridentate MA ligands and adip 2À anions. The adjacent single-layers are inter-linked to form a double-layer 2D structure through the AgÁ Á ÁAg interactions. Two CPs structurally vary from 2D sheet to 3D framework, which indicates that the different dicarboxylates and coordination modes of MA ligand have significant influence on the final structures. Moreover, the thermal stabilities of them were also discussed.
Canadian Journal of Chemistry, 1987
Crystals of (2-dimethylaminomethyl-3-pyridolato)dimethylgallium are monoclinic, a = 13.443(3), b = 6.7563(3), c = 13.046(2) Å, β = 100.38(1)°, Z = 4, space group I2/m, and those of bis[(8-quinolinolato)dimethylgallium] are monoclinic, a = 9.7340(4), b = 12.7135(5), c = 9.6843(4) Å, β = 117.014(3)°, Z = 2, space group P21/c. Both structures were solved by conventional heavy atom methods and were refined by full-matrix least-squares procedures to R = 0.044 and 0.032 for 1485 and 1567 reflections with I ≥ 3σ(I), respectively. The structure of [Me2Ga•O(C5H3N)CH2NMe2] consists of discrete monomeric molecules which contain tetrahedrally coordinated gallium atoms. The bidentate anionic 2-dimethylaminomethyl-3-pyridolate ligand coordinates Ga via the oxygen and amino nitrogen atoms (Ga—O = 1.892(3), Ga—N = 2.127(4), Ga—C = 1.950(5) and 1.939(6) Å). The structure of [Me2Ga•O(C9H6N)]2 consists of centrosymmetric dimers which contain a nearly planar system of seven fused rings. The Ga atoms ar...
Zeitschrift für anorganische und allgemeine Chemie, 2010
The controlled hydrolysis of heteroleptic magnesium amide, LMgN(SiMe 3 ) 2 (L = CH[C(Me)N(2,6-iPr 2 C 6 H 3 )] 2 ) with water afforded the corresponding hydroxide [LMg(OH)·THF] 2 as air and moisture sensitive compound. The presence of a sterically bulky β-diketiminate ligand prevents the self-condensation reaction of this hydroxide complex. Single crystal X-ray analysis shows that the hydroxide is dimeric in the solid state. Reaction of the magnesium amide or 201 LMg(Me)·OEt 2 with LAlMe(OH) generates the heterobimetallic species containing the Mg-O-Al moiety. Additionally, the reaction of methylmagnesiumchloride with the free ligand leads to complex L'MgCl (L' = CH[Et 2 NCH 2 CH 2 N(CMe)] 2 ). As revealed by the crystal structure, L'MgCl is a solvent free monomeric magnesium chloride complex that is analogues to the Grignard reagent.