Suraj Mondal

Syntheses, characterizations, and crystal structures of 3d–s/d10 metal complexes derived from two compartmental Schiff base ligands

The present investigation reports the syntheses, characterizations, and crystal structures of nine copper(II)/nickel(II)–s/d10 complexes, [CuIIL1NaI(ClO4)(CH3CN)] (1), [CuIIL1KI(ClO4)(CH3COCH3)] (2), [CuIIL2ZnIICl2]·CH3CN (3), [(CuIIL2)2NaI](ClO4)·CH3COCH3 (4), [(NiIIL1)2KI](ClO4) (5), [(CuIIL1)2CsI(ClO4)]·2CH3CN (6), [(NiIIL1)2CsI(ClO4)]·2H2O (7), [(CuIIL2)2SrII(H2O)2](NO3)2 (8), and [{CuIIL2LiI(H2O)}2(μ-H2O)](ClO4)2 (9), where H2L1 and H2L2 are two 3-methoxysalicylaldehyde-diamine (H2LOMe) ligands in which the diamine moieties are o-phenylenediamine and trans-1,2-diaminocyclohexane, respectively. Among these nine compounds, three (1, 2, and 3) are dinuclear, five (4, 5, 6, 7, and 8) are trinuclear, and 9 is tetranuclear. Trinuclear 6 and 7 are double-decker sandwich systems. Some (in 3 and 9) or all (in 1, 2, and 4–8) of the four oxygens of the O(phenoxo)2O(methoxy)2 compartment(s) are coordinated to the second metal ion (NaI in 1 and 4, KI in 2 and 5, ZnII in 3, CsI in 6 and 7, SrII in 8, and LiI in 9). The di/tri/tetranuclear molecules in 2–9 are self-assembled by weak attractions, such as hydrogen bonds/cation (KI) π/C–H π interactions. The following self-assemblies are observed: 1-D in 3, 7, and 9, 1-D ladder in 4, 2-D in 8, and 3-D in 2 and 5.

More surprising differences between two closely similar compartmental ligand families and another dinuclear synthon to stabilize dinuclear–mononuclear cocrystals

This paper presents syntheses, characterization, crystal structures and magnetic properties of two diphenoxo-bridged heterodinuclear CuIIMnII/CuIIFeII compounds [CuIIL1MnII(H2O)3](ClO4)2 (1) and [CuIIL1FeII(H2O)3](ClO4)2 (2) and two tetranuclear CuII3MnII/CuII3FeII compounds [{CuIIL2MnII(H2O)(MeOH)2}(CuIIL2)2](ClO4)2·MeOH (3) and [{CuIIL2FeII(H2O)(MeOH)2}(CuIIL2)2](ClO4)2·MeOH (4) derived from two 3-methoxysalicylaldehyde-diamine Schiff base compartmental ligands H2L1 and H2L2, in which the diamine counterpart comes from 1,3-diaminopropane and o-phenylenediamine, respectively. The two compounds 1 and 2 crystallize in the same space group (monoclinic P21/n) with practically identical unit cell parameters and are isomorphous. Similarly, the two compounds 3 and 4 crystallize in the same space group (monoclinic P21/c) with practically identical unit cell parameters and are isomorphous. The tetranuclear [{CuIIL2MII(H2O)(MeOH)2}(CuIIL2)2]2+ dication in 3 (M = Mn) and 4 (M = Fe) is a self-assembly of one diphenoxo-bridged dinuclear [CuIIL2MII(H2O)(MeOH)2]2+ dication and two mononuclear [CuIIL2] units. One mononuclear unit is self-assembled with the dinuclear unit by four bifurcated water⋯phenoxo/methoxy (O–H⋯O) hydrogen bonds and three π⋯π stacking interactions, while the second mononuclear unit is interlinked with the dinuclear unit by one methanol⋯phenoxo (O–H⋯O) hydrogen bond only. Clearly, compounds 3 and 4 are [2 × 1 + 1 × 2] cocrystals of one dinuclear and two mononuclear units. Variable-temperature magnetic susceptibility measurements of all the four compounds have been carried out, revealing moderate antiferromagnetic interaction between the copper(II) and manganese(II)/iron(II) in the dinuclear cores with J values (H = −2JS1S2) −29.1, −36.9, −15.9 and −20.2 cm−1, respectively. The magnetic properties are in line with those of previous related examples. Unique features in the structures of 1–4 have been discussed.

Synthesis and crystal structure of a triple-decker CuII3TlI2 complex: first example of a thallium(I) system in the imino-phenolate Schiff base ligand family

This report deals with the synthesis, characterization, and crystal structure of a heteropentanuclear CuII3TlI2 compound [(CuIIL)3TlI2](NO3)2 (1), where H2L=N,N′-ethylenebis(3-ethoxysalicylaldimine). This compound crystallizes in the monoclinic crystal system within space group C2/c. Each of the two symmetry related thallium(I) centers is located between a terminal and a common, central [CuIIL] by forming bonds with four phenoxo and three ethoxy oxygens. The three [CuIIL] moieties are parallel and hence 1 is a triple-decker system. Neighboring triple-decker moieties are interlinked by π⋯π stacking interaction and weak hydrogen bonds to generate 3-D self-assembly in 1. Salient features in the composition and structure of the title compound are discussed; the title compound is the first example of a thallium(I) system in imino-phenolate Schiff base family. Synthesis and crystal structure of [(CuIIL)3TlI2](NO3)2 is described, where H2L = N,N′-ethylenebis(3-ethoxysalicylaldimine). This is a sandwich, triple-decker system and the sole TlI complex derived from an iminophenolate ligand.

Bis(nitrate)diaquauranyl(VI) synthon to generate [1 x 2+1 x 1] and [1 x 1+1 x 1] co-crystalized 3d center dot center dot center dot 5f self-assemblies

The syntheses, characterization and crystal structures of four copper(II)/nickel(II)⋯uranyl(VI) self-assemblies of composition [{NiIIL1}2·{(UVIO2)(NO3)2(H2O)2}] (1), [{CuIIL2}2·{(UVIO2)(NO3)2(H2O)2}]·0.68H2O (2), [{NiIIL2}2·{(UVIO2)(NO3)2(H2O)2}] (3) and [{CuIIL3}·{(UVIO2)(NO3)2(H2O)2}]n (4) are described in this investigation (H2L1, H2L2 and H2L3 are the Schiff base ligands obtained on condensing 3-ethoxysalicylaldehyde with ethylenediamine, o-phenylenediamine and trans-1,2-diaminocyclohexane, respectively). Compounds 1 and 4 crystallized in the monoclinic P21/n and C2/c space groups, respectively, while compounds 2 and 3 crystallized in the triclinic space group P. Two water molecules of the [(UVIO2)(NO3)2(H2O)2] moiety in 1–4, have a linear H2O–U–OH2 arrangement. Each of these two water molecules in 1–3 interacts with the O(phenoxo)2O(ethoxy)2 compartment of a mononuclear copper(II) or nickel(II) moiety due to the formation of bifurcated hydrogen bonds between each of the two water hydrogen atoms and a pair of one phenoxo and one ethoxy oxygen atoms resulting in the interlinking of the two mononuclear 3d units by the [(UVIO2)(NO3)2(H2O)2] synthon and therefore these three compounds may be considered as supramolecular dimers. Compounds 1–3 are also two component [1 × 2 + 1 × 1] co-crystals consisting of two mononuclear copper(II) or nickel(II) units and one [(UVIO2)(NO3)2(H2O)2] moiety. On the other hand, in 4, two water molecules, from two different [(UVIO2)(NO3)2(H2O)2] moieties, interact with one O(phenoxo)2O(ethoxy)2 compartment resulting in the formation of a self-assembled one-dimensional topology. Again, since one mononuclear copper(II) unit and one [(UVIO2)(NO3)2(H2O)2] moiety exist in a single crystal in 4, this compound is a two component [1 × 1 + 1 × 1] co-crystal. The outcomes of the present study utilize [(UVIO2)(NO3)2(H2O)2] synthon to derive 3d⋯5f co-crystals, provide the first observation of the interaction of two water molecules with one O(phenoxo)2O(ethoxy)2 compartment, demonstrate the formation of supramolecular dimers and show the first example of a one-dimensional self-assembly resulting from water⋯O4 compartment hydrogen bonds, and the first example of [1 × 2 + 1 × 1] co-crystals in 3-ethoxysalicylaldehyde-diamine ligand system.