Decaaquabis(μ₃-4-hydroxypyridine-2,6-dicarboxylato)bis(4-hydroxypyridine-2,6-dicarboxylato)tetramanganese(II) 3.34-hydrate: a new three-dimensional open metal–organic framework based on a tetranuclear Mn^IIcomplex of chelidamic acid and undecameric stitching water clusters

Abstract

4-Hydroxypyridine-2,6-dicarboxylic acid (chelidamic acid, cdaH(3)) reacts with MnCl(2)·2H(2)O in the presence of 2-amino-4-methylpyrimidine in water to afford the tetranuclear title complex, [Mn(4)(C(8)H(3)NO(5))(4)(H(2)O)(10)]·3.34H(2)O, built through carboxylate bridging. The tetranuclear complex sits on a centre of inversion at (½, ½, ½). In the crystal, discrete undecameric (H(2)O)(10.34) water clusters (involving both coordinated and uncoordinated water molecules, with one site of an uncoordinated water molecule not fully occupied) assemble these tetranuclear Mn(II) complex units via an intricate array of hydrogen bonding into an overall three-dimensional network. The degree of structuring of the (H(2)O)(10.34) supramolecular association of water molecules observed in the present compound, imposed by its environment and vice versa, will be discussed in comparison to that observed for the (H(2)O)(14) supramolecular clusters in the case of the dinuclear complex [Mn(2)(cdaH)(2)(H(2)O)(4)]·4H(2)O [Ghosh et al. (2005). Inorg. Chem. 44, 3856-3862].

Crystal engineering with coordination compounds of 2,6-dicarboxy-4-hydroxypyridine and 9-aminoacridine fragments driven by different nature of the face-to-face π⋯π stacking

“…Up to now, several transitionmetal complexes based on chelidamic acid have been documented, many of them containing lanthanide metals. [8][9][10][11][12][13][14][15][16][17][18][19][20][21][22] At the initiation of this work, to the best of our knowledge, no proton transfer studies and complexes using this ligand with 9-aminoacridine had been reported (however as the study was being completed, three such complexes were reported, one of which is identical with the nickel complex prepared here). 20 Therefore, we selected chelidamic acid as the major ligand and 9-aminoacridine as an auxiliary (see Scheme 1) ligand for testing their reactions with some transition metal salts.…”

Structure and magnetism of a Mn(iii)–Mn(ii)–Mn(ii)–Mn(iii) chain complex

“…The pentagonal bipyramid coordination polyhedron around a manganese atom has been observed also in the crystal structure of various Mn(II) dipicolinato and chelidamato complexes. 15,[20][21][22][24][25][26][27] The Mn2⋯Mn2 separation is exactly 3.828(1) Å and it is comparable with Mn-Mn distances in centrosymmetric complexes of 27 The hydrogen bonding network and crystal packing of [Mn II 2 Mn III 2 (dipic) 6 (H 2 O) 4 ]•2CH 3 OH•4H 2 O are drawn in Fig. 2.…”