Comparative Study of Reactivity of Copper(II) Salts with N,N′‐Dipyridyl Ligands. Structural Diversity and Magnetic Properties

Abstract

The coordination chemistry of 1,2-bis(2-pyridyl)butadiyne (dpb) , 2,5-bis(2-pyridylethynyl)thiophene (dpet) (rigid ligands) and 4,4Ј-dipyridyldisulfide (4-dpds) (flexible ligand) with Cu(tfac) 2 (tfacϭ trifluoroacetylacetonate) and Cu(BF 4 ) · xH 2 O have been investigated in order to test the influence of different anions on the overall structure. Three of the resulting metal-organic assemblies have been determined. These crystal structures have shown that the geometry and coordinating properties of the corresponding anions together with the positional orientation of the nitrogen atoms in the ligands are essential in determining the final structures of the assemblies. So, reactions with Cu(tfac) 2 lead to

Different coordination modes and supramolecular aggregations in copper(II) pentane-2,4-dionato compounds with 2-pyridone and 3-hydroxypyridine

“…In comparison, medium-to-weak interactions exhibit rather long centroid-centroid distances ( [75] and (4-cyanopyridine)-cis-bis(1,1,1-trifluoropentane-2,4-dionato)copper(II) [10] with centroid-centroid contacts between two parallel metallacycles of 3.16 and 3.24 Å and with CuÁÁÁCc distances of 3.33 and 3.26 Å , respectively, and in Cu(acac) 2 (adenine) ethanol solvate with centroid-centroid contact of 3.23 Å with the angle between metallacycles 0.02°and CuÁÁÁCc distance of 3.23 Å [44]. Centroid-centroid distances in the range from 3.27 to 3.49 Å with parallel metallacycles or deviating from planarity by up to 0.03°and with CuÁÁÁCc distances in the range from 3.30 to 3.46 Å were observed in several examples [11,42,44,45,[76][77][78][79][80].…”

“…Only two crystal structures are known with octahedral coordination of copper in Cu(acac) 2 (L) 2 [7,8]. The presence of additional electron-withdrawing fluorine atoms on b-diketonato ligands enhances the acidic character of the central copper atom and octahedral coordination can be easily achieved [1,[9][10][11]. In these cases a five coordination of the copper atom can still be achieved by altering the molar ratio [1].…”

Joint Experimental and Computational Investigation of the Flexibility of a Diacetylene‐Based Mixed‐Linker MOF: Revealing the Existence of Two Low‐Temperature Phase Transitions and the Presence of Colossal Positive and Giant Negative Thermal Expansions

“…These ligandsh aveb een combined with Ag + ,C u + ,C u 2 + ,M n 2 + ,a nd Zn 2 + salts to prepare various kinds of cationic frameworks. [68][69][70][71][72][73][74][75][76][77][78] In addition, other rigid Nheterocyclic ligands containing ad iacetylene fragment have appeared in recent literature. [79][80][81] 1,6-Bis(1-imidazolyl)-2,4-hexadiyne( L1)( Scheme 1) is the neutral ligand used in this work.…”

Cobalt and Copper Coordination Polymers Containing Acetylacetonato‐Derived Ligands and Bidentate Pyridine Coligands: Synthesis, Crystal Structures and Magnetic Properties

“…So, the properties of the ligand, such as, length, geometry, coordination ability and relative orientation of the donor groups, can play a very important role in dictating polymer topology and even in affecting the formation of polymer versus oligomer versus molecule. [10,11] In contrast, the comparative study of the reactions of [Cu(acac) 2 ] and [Cu-(tfacac) 2 ] can show the different Lewis acidic character of the acetylacetonato complex used. It is noteworthy that very few complexes of [Cu(tfacac) 2 ] with N-donor bridging species have been reported.…”

“…It is noteworthy that very few complexes of [Cu(tfacac) 2 ] with N-donor bridging species have been reported. [7,10,11] Moreover, the fluorine atoms in [Cu(tfacac) 2 ] could promote a C-F···H-C hydrogen-bonding system, which could expand the onedimensional chain structure into two-dimensional networks.…”