Stable complexes Ti(1a)(2)2 and Ti(1b)(2)2, where 2 is the 6,6′-diphenyl-2,2′-biphenolato ligand and 1a and 1b ligands are 2,2′-bipyrimidine derivatives, are synthesized. The complex Ti(1b)(2)2 ...containing a diimine ligand substituted with long alkyl chains (C16) exhibits a liquid crystal behaviour. This property and self-assembling in the crystalline state are explained by the particular molecular conformation of the complexes.
The synthesis and characterisation of novel chelate nitrogen ligands with phasmidic tails (pyridine–triazole ligand 1b; 2,2′-bipyrimidine ligands 2b and 3b) as well as their titanium(iv) coordination ...complexes are reported. The analogous ligands 1a, 2a and 3a with methoxy substituents instead of the tails were also synthesized, together with titanium complexes that could be crystallographically characterised. A good agreement is noticed between analytical data of the complexes in solution (NMR) and in the solid state (X-ray diffraction). The complexes are overall robust on phases like alumina or silica, so that they could be characterised by TLC and sometimes chromatographied. Supramolecular architectures were generated from an equimolar solution of titanium(iv) isopropoxide, ligand 1a and a polyphenol ligand 5-H4, leading to a double-stranded helicate characterised by MS, NMR and crystallography, which was then converted into a trinuclear complex as shown by MS and NMR DOSY data. The liquid-crystalline behaviour of the ligands 1b, 2b and 3b incorporating the long alkyl tails and that of the complexes derived from these ligands have been investigated.
The macrocyclic ligand calix4arene (
L1
) and its sulphur-containing analogue thia4calixarene (
L2
) are promising precursors for functional molecular materials as they offer rational ...functionalization with various organic groups. Here, we present the first example of lanthanide-based coordination polymers built from the macrocyclic thiacalix4arene backbone bearing four carboxylic moieties, namely, ligand
H
4
L3
. The combination of
H
4
L3
with the Tb
3+
and Dy
3+
cations led to the formation of 1D ladder-type coordination polymers with the formula Ln
III
HL3
DMF
3
·(DMF) (where DMF = dimethylformamide and Ln = Tb or Dy, denoted as
HL3-Tb
and
HL3-Dy
), which resulted from the coordination of the lanthanide cations with the partially deprotonated ligand
HL3
3−
that behaved as a T-shape connector. The coordination sphere around the metal was completed by the coordinated DMF solvent molecules. By combining both Tb
3+
and Dy
3+
cations, isostructural heterobimetallic solid solutions
HL3-Tb
1−
x
Dy
x
were also prepared.
HL3-Tb
and
HL3-Dy
showed visible light photoluminescence originating from the f-f electronic transitions of pale green emissive Tb
3+
and pale yellow emissive Dy
3+
with efficient sensitization by the functionalized thia4calixarene ligand
HL3
. In the
HL3-Tb
1−
x
Dy
x
solid solutions, the Tb/Dy ratio governed both the emission colour as well as the emission quantum yield, which reached even 28% at room temperature for
HL3-Tb
. Moreover,
HL3-Dy
exhibited a slow magnetic relaxation effect related to the magnetic anisotropy of the dodecahedral Dy
3+
complexes, which were well isolated in the crystal lattice by expanded organic spacers.
The single crystals of the two isostructural Tb
3+
- and Dy
3+
-based coordination polymers (
HL3-Tb
and
HL3-Dy
) were structurally characterized, and their photophysical properties were investigated, together with their corresponding solid solutions.
Stable complexes Ti(1a)(2)2 and Ti(1b)(2)2, where 2 is the 6,6'-diphenyl-2,2'-biphenolato ligand and 1a and 1b ligands are 2,2'-bipyrimidine derivatives, are synthesized. The complex Ti(1b)(2)2 ...containing a diimine ligand substituted with long alkyl chains (C16) exhibits a liquid crystal behaviour. This property and self-assembling in the crystalline state are explained by the particular molecular conformation of the complexes.
The synthesis and binding propensity towards copper of new ligands based on calix4arene and thiacalix4arene backbones in 1,3-Alternate conformation bearing four iminocatechol coordinating units are ...described.
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•Calix4arene and thiacalix4arene multivalent ligands in 1,3-Alternate conformation.•Macrocyclic ligands with four divergently disposed iminomethyl-catechol units.•Binuclear Copper(II) complexes with 03N deformed square planar coordination sphere.•Binding propensy: solid-state study and behaviour in solution.
Two new multivalent ligands 1 and 2, based on calix4arene and thiacalix4arene backbones in 1,3-Alternate conformation, bearing four iminocatechol coordinating units have been prepared and structurally characterized both in solution and in the crystalline phase. Combinations of compounds 1 and 2 with Cu(II) afford neutral binuclear complexes 1-Cu2 and 2-Cu2, characterized in the solid state. In both cases, the metal centre, surrounded by a O3N set of heteroatoms, adopts a deformed square planar coordination geometry. In solution, the propensity of ligands 1 and 2 to bind M2+ cations ((M=Co, Ni, Cu and Zn) was also demonstrated. In 1/1 MeOH/CHCl3 mixture and at room temperature, the following stability sequence Ni2+<Zn2+<Co2+≪Cu2+ was observed for both binuclear 1-M2 and 2-M2 complexes.
The combination, under mild conditions, of the methylenecarboxylic-appended tetramercaptotetrathiacalix4arene (TMTCA) derivative 4 , blocked in the 1,3-alternate conformation, with acetate salts of ...octahedral copper( ii ), manganese( ii ), nickel( ii ) and zinc( ii ) leads to the formation, in the crystalline state, of high dimensional coordination networks. Depending on the nature of the used metal cations and bases (pyridine or non-coordinating Et 3 N), six new different high-dimensional coordination polymers have been evidenced, presenting 4 different coordination patterns. All the compounds present a metal/ 4 ratio equal to 2/1. The formation of a 2D grid-like compound ( 4 -Zn 2 (Py) 4 ) and three different pseudodiamondoid-like 3D compounds ( 4 -Co 2 (Py) 6 (H 2 O) 2 , 4 -Ni 2 (Py) 6 (H 2 O) 2 , 4 -Mn 2 (Py) 4 (MeOH) 2 , 4 -Mn 2 (DMF) 2 (MeOH) 4 and 4 -Zn 2 (MeOH) 4 ) is observed.
Herein, the multistep synthesis of eight new ligands based on either calix4arene or thiacalix4arene backbone blocked in a 1,3-alternate conformation was achieved. Both types of backbones were ...functionalized with pyridyl coordinating units using either imino or amino junctions. The introduction of the pyridyl units was achieved using either the position 3 ( meta ) or 4 ( para ) of the aromatic moiety. Moreover, four out of the eight ligands were structurally investigated in the solid state via X-ray diffraction methods on single crystals.
Three new organic tectons (2–4) based on the p-tert-butylthiacalix4arene backbone, blocked in the 1,3-alternate conformation, bearing four pyridyl coordinating moieties, have been synthesised and ...characterised in the solid state. The ligands are positional isomers and differ by the position of the N atom on the pyridyl unit (ortho for 2, meta for 3 and para for 4). Their combination with the Ag+ cation leads, reproducibly, to the formation of 2- and 3-D infinite silver coordination networks. Independent of the nature of the anion, the combination of 2 offering four (N,S) type chelates with the Ag+ cation affords an unprecedented diamond type 3D network. Both 3 and 4, behaving as tetrakis monodentate ligands, lead to the formation of 2-D architectures.
Combinations of six new coordinating tectons ( 3–8 ) tetrakis-pyrazolyl appended calix4arenes, blocked in 1,3-A conformation, based on 1 (tetrathiacalix4arene) and 2 ...(tetrathiatetramercaptocalix4arene) derivatives, with AgX salts (X = NO 3 − , BF 4 − , XF 6 − (X = P, As and Sb)) lead to nine new silver coordination networks. The flexible nature of tectons 3–8 (length of the spacer between the macrocycle and the pyrazolyl coordinating unit), their high number of potential coordinating sites and the loose coordination demand of Ag + cation lead to the formation of a large variety of networks with different dimensionality: from 1D ( 5 -AgSbF 6 , 5 -AgBF 4 , 7 -AgSbF 6 and 8 -AgNO 3 ) to extended 2D ( 6 -AgBF 4 and 8 -AgSbF 6 ) and to a series of three isostructural porous diamond-like 3D architectures ( 6 -AgXF 6 (X = P, As and Sb)).
A series of thiacalix4arene derivatives blocked in the 1,3-alternate conformation and bearing four carboxylic acids have been designed and synthesized. These compounds, owing to the H-bond donor (OH ...moiety) and acceptor (C&z.dbd; O group) nature of the carboxylic acid moieties, behave as self-complementary tectons and lead to the formation of tubular 1D H-bonded networks in the crystalline phase. Upon deprotonation of the self-complementary neutral compounds, i.e. transformation of carboxylic acid moieties into carboxylates, anionic tectons are generated. Due to their propensity to form H-bonded networks in the presence of a dicationic H-bond donor tecton of the cyclic bis-amidinium type, designed to behave as a molecular staple interconnecting two carboxylates moieties, 1- and 2-D H-bonded networks are formed under self-assembly conditions.
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