Solvent-Dependent Formations of Supramolecular Isomers and a Single-Crystal to Single-Crystal Transformation from a Cyclic Dimer Complex to a One-Dimensional Coordination Polymer

Abstract

Solvent-dependent supramolecular isomers of a tripodal ligand incorporating two para-pyridylmethyl arms, N-naphthylmetyl-N,N-bis­(4-pyridylmethyl)­amine (L), are reported. A combination of L and copper­(II) hexafluoroacetylacetonate, Cu­(hfac)2, in methanol afforded a cyclic dimer complex [Cu2(L)2(hfac)4]·CH3OH (1). In chloroform/methanol, the same reaction furnished an infinite one-dimensional (1D) complex {[Cu2(L)2(hfac)4]·2CHCl3} n (2). When the cyclic dimer 1 was immersed in chloroform/ether, its transformation to the 1D coordination polymer 2 was observed in an single-crystal to single-crystal manner. In silver­(I) triflate complexations, three supramolecular isomers (3–5) were isolated. In chloroform/methanol, a multichannel-type three-dimensional (3D) coordination polymer {[Ag­(L)]­(CF3SO3)·0.5CHCl3} n (3) was isolated. In isomer 3, the Ag atom link L ligands alternately to form a helix, and these are linked by Ag–Ag contacts to generate an etb topology. In acetonitrile/methanol, a multichannel-type 3D coordination polymer {[Ag­(L)]­(CF3SO3)·CH3CN} n (4) was isolated. In isomer 4, six Ag atoms and six L ligands form an Ag6 L 6 hexagonal unit, and these are linked via Ag–Ag contacts, resulting in a pcu-h topology. In toluene/methanol/acetonitrile, a cross-linked ladder-type coordination polymer {[Ag4(L)4(CF3SO3)2]­(CF3SO3)2·3­(toluene)} n (5) was obtained. The isomer 5 is composed of two types of ladders crossed showing a new topology. Considering the formation of the (π–π)-(Ag–Ag)-(π–π) unit in 3–5, it is suggested that the anion–solvent interaction could be a major reason.

R-Substituent-Induced Structural Diversity and Single-Crystal to Single-Crystal Transformation of Coordination Polymers: Synthesis, Luminescence, and Magnetic Behaviors

“…Thus, the oxygen atom (O2) is considered to coordinate weakly to the Zn­(II) ion, which may be the reason why SCSC transformation can be carried out and finally exists in the form of 6 . In addition, among several factors, the transformation might be driven by the solvation effect . So far, it is extremely rare to realize the SCSC transformation under such mild conditions, and more experimental support is needed in future work.…”

“…In addition, among several factors, the transformation might be driven by the solvation effect. 32 So far, it is extremely rare to realize the SCSC transformation under such mild conditions, and more experimental support is needed in future work.…”

“…Compared with the original compound, the new compound caused by the change of the M–L bond often has a different coordination number, geometry, dimensionality, and physical or chemical properties. − Recently, we have observed water and temperature-induced SCSC transitions in three copper-based CPs in which some M–L coordination bonds are relatively weak in thermodynamics or kinetics (e.g., coordination bond of monodentate carboxylate O with metal) . Generally speaking, flexible or semirigid ligand self-assembly products seem to be more sensitive to the above factors including solvents. − Precisely, the long alkyl chain of n -butyl in the n -BuO-H 2 ip ligand will make the configuration of the ligand more flexible and at the same time reduce the rigidity, which makes it possible for ligands with flexible characteristics to have the potential to build a variety of backbones. Moreover, the functionality of CPs can be favorably modified by SCSC transformation.…”

Synthesis, crystal structure and photophysical properties of bis[2,6-difluoro-3-(pyridin-2-yl)pyridine-κN](trifluoromethanesulfonato-κO)silver(I)

“…Despite these investigations, reports regarding the structures and photoluminescence properties of 2,3 0 -bipyridine-based group-11 metal complexes are scarce, and related research is limited (Li et al, 2019). Among the group-11 elements, coordination polymers of Ag I have been demonstrated to exhibit structural diversity as a result of the d 10 configuration of the metal ion (Lee et al, 2020). Moreover, the various coordination environments around the Ag I centre are generally constructed by the ligands, solvent molecules, and counter-anions (Lee et al, 2016).…”

Structural transformation of copper coordination complexes accompanied with chiral transformation

“…[16][17][18][19][20][21] It is worth noting that small variations in the synthesis process can affect the final result, which is more obvious for multi-site and soft ligands, 22 and sometimes such differences can be large. In addition, many other factors, such as temperature, 8 solvents, 23,24 reaction pH, 25,26 additives, 27 surfactants, 28 auxiliary ligands, 29 guest molecules, 30 reaction sequence, 17 and light, 31 affect the self-assembly process, hence accurate prediction of the crystal structure is still a major challenge in crystal engineering.…”