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Metal-mediated assembly allows us to combine an achiral emissive ligand A with different chiral ligands (such as B) in a non-statistical fashion, obtaining Pd 2 A 2 B 2 heteroleptic cages showing circularly polarized luminescence (CPL). By using the 'shape complementary assembly' (SCA) strategy, the cages are exclusively obtained as cis -Pd 2 A 2 B 2 stereoisomers, as confirmed by NMR, MS and DFT analyses. Their unique chiroptical properties derive from the synergy of all the building blocks. Ligand B imparts the chiral information of its aliphatic backbone, comprising two stereogenic sp 3 carbon centres, to the overall structure, causing CD and CPL signal induction for the chromophore on ligand A. The heteroleptic cage shows CPL with a | g lum | value of 2.5 × 10 -3 , which is 3-times higher than that for a progenitor based on aromatic helical building block H, thus opening a rational route towards optimizing the CPL properties of self-assembled nanostructures in a modular way.

Two-dimensional (2D) chirality has been actively studied in view of numerous applications of chiral surfaces such as in chiral resolutions and enantioselective catalysis. Here, we report on the expression and amplification of chirality in hybrid 2D metallosupramolecular networks formed by a nucleobase derivative. Self-assembly of a guanine derivative appended with a pyridyl node was studied at the solution-graphite interface in the presence and absence of coordinating metal ions. In the absence of coordinating metal ions, a monolayer that is representative of a racemic compound was obtained. This system underwent spontaneous resolution upon addition of a coordinating ion and led to the formation of a racemic conglomerate. The spontaneous resolution could also be achieved upon addition of a suitable guest molecule. The mirror symmetry observed in the formation of the metallosupramolecular networks could be broken via the use of an enantiopure solvent, which led to the formation of a globally homochiral surface.

New ligand based on p - tert butyltetrathiacalix[4]arene blocked in 1,3-alternate conformation, was achieved via a multistep synthesis with the introduction of thiomethylpropoxy groups on the lower rim which leads to a neutral tecton. The combination of this p - tert butyltetrathiacalix[4]arene ( p -TCA-2 ), in 1, 3-alternate imposed conformation, with tetrahedral Ag(I)SbF 6 salt, leads to the formation of neutral, new 2-D coordination network, which was structurally investigated in the solid state by X-ray diffraction methods on a single crystal., (© TÜBİTAK.)

The combination of four iso- nicotinate appended tetrathiacalix[4]arene ( TCA-1 ) in 1,2-alternate imposed conformation behaving as neutral tectons with Co(II)Cl 2 and Hg(II)Cl 2 metallic salts, leads to the formation of neutral, new coordination networks. Indeed, the tetrasubstituted TCA-1 derivative leads to a 1D coordination polymer with Co(II)Cl 2 and a 2D grid-like network with, Hg(II)Cl 2 . The effect of the nature of the metal used on the dimensionality was demonstrated by X-ray diffraction studies on a single crystal., (© TÜBİTAK.)

Seven isostructural heterometallic luminescent (Ir,Cd) coordination polymers were prepared upon the combination of tris-chelate cationic Ir(III) complexes behaving as metalloligands with Cd(II) salts. Three octahedral Ir(III) complexes have been considered in the present report. They consist of a bipyridine unit functionalised with 3-pyridyl moieties as peripheral coordinating sites and two 2-phenylpyridyl cyclometalating derivatives. Three cadmium halide salts CdX 2 (X = Cl, Br, I) were used and rearranged themselves during the self-assembly process with the metallatectons to afford a dianonic trinuclear Cd node [Cd 3 X 8 ] 2- . Seven out of the nine possible metallotecton-metal salt combinations could be characterised in the crystalline phase by X-ray diffraction on single crystals proving the isostructurality of the seven extended architectures studied. All of the CPs are luminescent with small shifts observed in the emission wavelength compared to the discrete complexes. Depending on the degree of fluorination of the two cyclometalating units, tuning of the emission wavelength of the discrete complexes as well as of the resulting coordination polymers is achieved.

The self-assembly of a nickel-porphyrin derivative (Ni-DPPyP) containing two pyridyl coordinating sites and two pentyl chains at trans meso positions was studied with scanning tunneling microscopy (STM), X-ray photoelectron spectroscopy (XPS) and low energy electron diffraction (LEED) on Au(111). Deposition of Ni-DPPyP onto Au(111) gave rise to a close-packed network for coverages smaller or equal to one monolayer as revealed by STM and LEED. The molecular arrangement of this two-dimensional network is stabilized via hydrogen bonds formed between the pyridyl's nitrogen and hydrogen atoms from the pyrrole groups of neighboring molecules. Subsequent deposition of cobalt atoms onto the close-packed network and post-deposition annealing at 423 K led to the formation of a Co-coordinated hexagonal porous network. As confirmed by XPS measurements, the porous network is stabilized by metal-ligand interactions between one cobalt atom and three pyridyl ligands, each pyridyl ligand coming from a different Ni-DPPyP molecule., (© 2021 The Authors. Chemistry - A European Journal published by Wiley-VCH GmbH.)

During the past decade, it has been shown that light-matter strong coupling of materials can lead to modified and often improved properties which has stimulated considerable interest. While charge transport can be enhanced in n-type organic semiconductors by coupling the electronic transition and thereby splitting the conduction band into polaritonic states, it is not clear whether the same process can also influence carrier transport in the valence band of p-type semiconductors. Here we demonstrate that it is indeed possible to enhance both the conductivity and photoconductivity of a p-type semiconductor rr-P3HT that is ultrastrongly coupled to plasmonic modes. It is due to the hybrid light-matter character of the virtual polaritonic excitations affecting the linear response of the material. Furthermore, in addition to being enhanced, the photoconductivity of rr-P3HT shows a modified spectral response due to the formation of the hybrid polaritonic states. This illustrates the potential of engineering the vacuum electromagnetic environment to improve the optoelectronic properties of organic materials.

The macrocyclic ligand calix[4]arene (L1) and its sulphur-containing analogue thia[4]calixarene (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 thiacalix[4]arene 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 HL3DMF 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 thia[4]calixarene 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., Competing Interests: There are no conflicts to declare., (This journal is © The Royal Society of Chemistry.)

Assembly of a novel ethylenedithio-tetrathiafulvalene (EDT-TTF) derivative bearing two adjacent 4-thiopyridyl groups with M(NCS)2 nodes (M = Fe, Co) leads to two isostructural 1D coordination polymers showing an enhancement of their electronic conductivity by six orders of magnitude (10-6vs. 10-12 S cm-1), upon surface oxidation by iodine and subsequent generation of EDT-TTF-based radicals.

A novel linear binuclear Zn(ii)/2,2'-bis-dipyrrin double-stranded helicate bearing peripheral p-benzaldehyde moieties has been strapped by formation of imine bonds upon reaction with m-xylylenediamine and characterized by 1H- and 13C-NMR spectroscopy, UV-Visible spectroscopy and high-resolution mass spectrometry.

The chemical oxidation of a hydrogen bonded network, formed upon combination of a hydrogen bond donor dication (1 2+ , a dicationic bis-amidinium organic moiety bearing four propyl chains) with [Fe III/II (CN) 6 ] 3-/4- anions has been studied using vibrational spectroscopies. The postsynthetic oxidation of the microcrystalline powder of X 2 1 3 -[Fe II (CN) 6 ] 2 (X = Na, K, and Cs) by S 2 O 8 2- into 1 3 -[Fe III (CN) 6 ] 2 appeared to be partial for X = K + and Cs + and total for Na 2 1 3 -[Fe II (CN) 6 ] 2 . It corresponds to a two-step process involving a second order reaction. The reaction time appears to be dependent on the nature of the alkali cation and is faster for X = Na + . The integrity of the hydrogen bonded network, after oxidation, was also confirmed by powder X-ray diffraction. The flexible nature of the hydrogen bonded network allows alkali cation motions within the network during the oxidation process. In addition, the investigation of the electrochemical behavior evidenced an amorphous deposition on a gold electrode immersed into a solution containing (1 2+ and [Fe III (CN) 6 ] 3- ) after 100 cycles. This is the first evidence of an electrochemical ion intercalation for a molecular hydrogen bonded network.

An achiral organic tecton bearing four coordinating sites of the pyridyl type leads to the formation of iso-structural 3D helical coordination polymers when combined with Co(SCN) 2 and Fe(SCN) 2 achiral neutral complexes. Their formation occurs during the self-assembly process in the solid state, which leads to crystals composed of homochiral coordination polymers.

New polymer capsules (PCs) were obtained using a crystal crosslinking (CC) method on core-shell MOF crystals. The latter are based on the epitaxial growth of two isostructural coordination polymers which are then selectively crosslinked. Decomposition of the non-reticulated phase leads to new PCs, possessing a well-defined hollow cubic shape reflecting the heterostructure of the template.

The design and synthesis of a novel family of molecular turnstiles T1-T5 were achieved. All five turnstiles are based on a stator and a rotor covalently interconnected. While turnstiles T1-T2 are based on a symmetric stator equipped with two coordinating pyridyl units and a rotor bearing either a pyridyl or p-dimethylaminopyridyl coordinating moiety, the two non-symmetric turnstiles T4 and T5 are based on a stator bearing only a single pyridyl unit and the same rotor as T1 and T2 mentioned above. The switching between the open (T1-T5) and the closed (T-M) states of the turnstiles by metal cations (M = Ag + or Pd 2+ ) was investigated in solution by using 1D and 2D NMR techniques. The locking of the rotational movement leading to the closed state of the turnstile was achieved upon addition of the Ag + cation through its simultaneous binding by both pyridyl moieties of the stator and the rotor. The unlocking process leading back to the open state was achieved by the addition of Et 4 NBr. For the symmetric turnstiles T1 and T2, bearing two pyridyl units on the stator, the binding of the Ag + cation leads to an oscillating phenomenon between the two energetically equivalent closed states. However, in the case of turnstile T1, the oscillating process could be prevented by blocking the rotational movement using PdCl 2 as the locking agent. Owing to the emissive nature of the stator, the open and closed states of the turnstiles were investigated by steady state and time-resolved photophysical methods. The photo-excitation of the turnstiles in their open state leads to an intense near-UV to deep-blue emission with short-lived excited states and a singlet intra-ligand charge transfer ( 1 ILCT) character. Upon binding of the Ag + cation, sizeable bathochromic shifts and a substantial decrease of PLQY were observed. Finally, the coordination of PdCl 2 , which possesses lower-lying excited states with metal-centered (MC) and ligand-to-metal charge transfer (LMCT) character, completely quenches the photoluminescence.

Photosensitizing and emission properties of P(v) porphyrins were studied. The nature of the axial ligands, occupying the apical position on the P centre adopting an octahedral coordination geometry, strongly influences singlet oxygen generation and charge transfer and allows switching between the two processes.

A non-interpenetrated metal-organic framework with a paddle-wheel secondary building unit has been activated by direct thermal evacuation, guest exchange with a volatile solvent, and supercritical CO 2 drying. Conventional thermal activation yields a mixture of crystalline phases and some amorphous content. Exchange with a volatile solvent prior to vacuum activation produces a pure breathing phase with high sorption capacity, selectivity for CO 2 over N 2 and CH 4 , and substantial hysteresis. Supercritical drying can be used to access a guest-free open phase. Pressure-resolved differential scanning calorimetry was used to confirm and investigate a systematic loss of sorption capacity by the breathing phase as a function of successive cycles of sorption and desorption. A corresponding loss of sample integrity was not detectable by powder X-ray diffraction analysis. This may be an important factor to consider in cases where flexible MOFs are earmarked for industrial applications., (© 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.)

Combinations of two enantiomerically pure organic tectons 1 and 3 with either Zn(ii) or Cu(ii) cations lead to the formation of four homochiral 3D networks among which two, 1-Cu and 3-Cu, are robust porous crystals displaying homochiral cavities and permanent microporosity. 3-Cu porous crystals capture 66% and 20% of l- and d-tryptophan, respectively, after 30 min of adsorption.

Combinations of a neutral Pt(ii) organometallic tecton bearing two triphenylphosphine and two 3-ethynylpyridyl coordinating moieties in trans positions with MX 2 complexes (M = Co(ii) and X = Cl - or Br - and M = Zn(ii) and X = Cl - ) lead to the formation of isostructural 1D heterobimetallic coordination compounds. By 3D epitaxial growth processes, using coordination bonding, heterotrimetallic core-shell crystals are generated by the growth of crystalline layers on seed crystals.

Coordination of 2,2'-bisdipyrrin based ligands to Zn(ii) cations leads to the formation of binuclear helicates with pre-organized pyrrolic strands as well as peripheral aromatic moieties for Ag-π interactions, thus affording crystalline heterometallic networks upon further interactions with Ag(i) salts without the assistance of additional heteroatom-based coordinating units.

A new cationic molecular turnstile based on a P(V) porphyrin backbone bearing two pyridyl interaction sites, one at the meso position of the porphyrin and the other on the handle connected to the porphyrin through P-O bonds, was designed and synthesized. The dynamic behavior of the turnstile 2, investigated by 1D and 2D 1 H NMR techniques, showed that in the absence of an effector, the turnstile is in its open state and undergoes a free rotation of the rotor (the handle) around the stator (the porphyrin backbone). In the presence of an external effector such as Ag + cation or H + , the turnstile is switched to its closed states 2-Ag + and 2-H + , respectively. The locking/unlocking process is reversible and may be achieved by precipitation of AgBr upon addition of Et 4 NBr in the case of the silver-locked turnstile or by addition of Et 3 N in the case of the proton-locked turnstile.

The generation, under self-assembly conditions, of coordination polymers on surface based combinations of a terpyridine-antracene-pyridine based tecton and Co(II) or Pd(II) cations is primarily governed by the coordination geometry of the metal center (octahedral and square planar respectively). While the octahedral Co(II) based polymer self-assembles in insulating films exhibiting randomly oriented crystalline domains, the planarity of Pd(II) based polymers leads to the formation of conductive π-π stacked fibrillar structures exhibiting anisotropically oriented domains. In the latter case, the favorable Pd-Pd and anthracene-anthracene wavefunction overlaps along the fiber direction are responsible for the large electronic couplings between adjacent chains, whereas small electronic couplings are instead found along individual polymer chains. These results provide important guidelines for the design of conductive metal coordination polymers, highlighting the fundamental role of both intra- as well as inter-chain interactions, thus opening up new perspectives towards their application in functional devices.

Both for fundamental and applied sciences, the design of complex molecular systems in the crystalline phase with strict control of order and periodicity at both microscopic and macroscopic levels is of prime importance for development of new solid-state materials and devices. The design and fabrication of complex crystalline systems as networks of crystals displaying task-specific properties is a step toward smart materials. Here we report on isostructural and almost isometric molecular crystals of different colors, their use for fabrication of core-shell crystals, and their welding by 3D epitaxial growth into networks of crystals as single-crystalline entities. Welding of crystals by self-assembly processes into macroscopic networks of crystals is a powerful strategy for the design of hierarchically organized periodic complex architectures composed of different subdomains displaying targeted characteristics. Crystal welding may be regarded as a first step toward the design of new hierarchically organized complex crystalline systems.

With the aim of combining luminescence and chirality in heterometallic Ir(III)-Cd(II) coordination networks, synthetic strategies for the formation of new Ir(III)-based chiral metallatectons ([Ir(dFppy)2(1)][PF6]), both as a racemic mixture of Δ and Λ enantiomers (rac-[Ir(dFppy)2(1)][PF6]) and as enantiopure complexes (Δ-[Ir(dFppy)2(1)][PF6] and Λ-[Ir(dFppy)2(1)][PF6]), were developed. The final compounds were characterized both in solution and in the crystalline phase. Notably, their crystal structures were determined by single crystal X-ray diffraction, and their photophysical properties in solution and in the solid state were investigated. Combination of the cationic linear metallatecton with Cd(2+) iodide salt ([CdI3](-)), behaving as an anionic two-connecting node, leads to the formation of 1D chiral and neutral heterometallic Ir(III)-Cd(II) luminescent coordination networks both as a racemic mixture and as enantiomerically pure infinite architectures. The latter have been structurally studied in the solid state by X-ray diffraction both on single crystals and on microcrystalline powders. The infinite coordination networks display phosphorescence in the solid state at ca. 600 nm upon excitation at 400 nm.

A chiral-at-metal Ir(III) organometallic metallatecton was synthesised as a racemic mixture and as enantiopure complexes and combined with Cu(II) to afford a heterobimetallic (Ir,Cu) grid-type 2D coordination network.

Combinations of a neutral organometallic tecton based on a square planar Pt(ii) complex bearing two triphenylphosphine groups and two 4-ethynylpyridyl coordinating moieties in trans positions, with various metal halides (MX2, M = Co(ii), Ni(ii), Cd(ii), X = Cl(-) or Br(-)) lead to the formation of 2D grid type heterobimetallic coordination networks in the crystalline phase.

Playing with the competition between H- and coordination-bonds, a bi-stable unsymmetrical organometallic turnstile was designed and its dynamic behaviour was studied in solution using NMR techniques. The turnstile, bearing two differentiated interaction sites, is based on a stator, composed of a square planar Pt(II) centre equipped with one pyridyl group and one phenol moiety, connected to a symmetrical rotor bearing a pyridyl unit as either a H-bond acceptor or as a monodentate coordinating site. Whereas in the absence of a metallic effector, the turnstile is locked by a H-bond formed between the phenol moiety located on the stator and the pyridyl group of the rotor, in the presence of Ag(+) cations, the turnstile switches to another closed state resulting from the simultaneous binding of the cations by pyridyl units belonging to both the stator and the rotor. The switching process was shown to be reversible.

The self-assembly of multiple molecular components into complex supramolecular architectures is ubiquitous in nature and constitutes one of the most powerful strategies to fabricate multifunctional nanomaterials making use of the bottom-up approach. When spatial confinement in two dimensions on a solid substrate is employed, this approach can be exploited to generate periodically ordered structures from suitably designed molecular tectons. In this study we demonstrate that physisorbed directional periodic arrays of monometallic or heterobimetallic coordination polymers can be generated on a highly oriented pyrolitic graphite surface by combinations of a suitably designed directional organic tecton or metallatecton based on a porphyrin or nickel(II) metalloporphyrin backbone bearing both a pyridyl unit and a terpyridyl unit acting as coordinating sites for CoCl2. The periodic architectures were visualized at the solid/liquid interface with a submolecular resolution by scanning tunneling microscopy and corroborated by combined density functional and time-dependent density functional theory calculations. The capacity to nanopattern the surface for the first time with two distinct metallic centers exhibiting different electronic and optical properties is a key step toward the bottom-up construction of robust multicomponent and, thus, multifunctional molecular nanostructures and nanodevices.

Coordination of two 2,2'-bisdipyrrin ligands, bearing methyl ester or methylthioether peripheral groups, with Zn(II) cations leads not only to the formation of the expected linear helicates but also concomitantly to novel tri- and tetra-nuclear circular species that have been isolated and fully characterized in solution and by X-ray diffraction.

The self-assembly of a metal-free porphyrin bearing two pyridyl coordinating sites and two pentyl chains at trans meso positions was investigated under ultrahigh vacuum on a Ag(111) surface by scanning tunneling microscopy (STM). The STM measurements revealed a well-ordered close-packed structure with a rhombic unit cell for coverages ≤1 monolayer with their molecular plane parallel to the surface. The growth direction of the molecular islands is aligned along the step edges, which are restructured due to molecule-substrate interactions. The shorter unit cell vector of the molecular superstructure follows the〈1-10〉direction of the Ag(111) substrate. Hydrogen bonds between pyridyl and pyrrole groups of neighboring molecules as well as weak van der Waals forces between the pentyl chains stabilize the superstructure. Deposition of cobalt atoms onto the close-packed structure at room temperature leads to the formation of a hexagonal porous network stabilized by metal-ligand bonding between the pyridyl ligands and the cobalt atoms. Thermal annealing of the Co-coordination network at temperatures >450 K results in the transformation of the hexagonal network into a second close-packed structure. Changes in the molecule-substrate interactions due to metalation of the porphyrin core with Co as well as intermolecular interactions can explain the observed structural transformations.

A strategy for the conversion of homometallic coordination networks into mixed metal-organic frameworks (MM'MOFs) is proposed. Ni(II) complexes of dipyrrin (dpm) ligands bearing peripheral pyridyl or imidazolyl units have been shown to self-assemble into coordination polymers with the metal cation in an octahedral environment coordinated to two bis-pyrrolic chelates and two neutral monodentate coordinating units such as pyridyl or imidazolyl moieties. Taking advantage of the chelate effect, the two monodentate units may be replaced by a diimine ligand leading to the disassembly of the networks by the formation of discrete soluble complexes. The latter can be employed as metallatectons for the construction of heterometallic architectures upon reaction with a secondary metal salt. This approach was applied using either 1,10-phenanthroline (phen) or 2,2'-bipyrimidine (bpm) as chelates leading to a series of mono- and binuclear metallatectons of the (phen)Ni(dpm)2 and (bpm)[Ni(dpm)2]2 type. Subsequent assembly with CdCl2 afforded either interpenetrated 2D grid-type architectures or 3D MM'MOFs.

A molecular turnstile based on a hydroquinone luminescent hinge bearing two divergently oriented pyridyl units behaving as a rotor and equipped with a handle composed of a tridentate coordinating site considered as the stator was synthesized and its structure was studied in the solid state by X-ray diffraction on single crystal. Its dynamic behaviour in solution was investigated by 1- and 2-D NMR experiments which revealed the free rotation of the rotor around the stator. The rotational movement was locked upon addition of Pd(ii) simultaneously complexed by the tridentate moiety of the stator and one of the two monodentate pyridyl sites of the rotor. Interestingly, whereas the open state of the turnstile was luminescent, for its closed state the emission was quenched by the heavy atom effect of Pd(ii).

The nanostructuring of the graphite surface with 2D coordination networks, based on a combination of an acentric porphyrin tecton bearing two divergently oriented monodentate pyridyl units and a CoCl2 metallatecton, behaving as a four connecting node, was achieved at the solid-liquid interface and characterized by scanning tunnelling microscopy.

The hysteresis and dynamics of the phase transition of the perovskite salt [Pb(II)I4(2-),(C12H25NH3(+))2] is shown to be significantly modified when strongly coupled to the vacuum field inside a micro-cavity. The transition barrier is increased and the hysteresis loop is enlarged, demonstrating the potential of controlling the electromagnetic environment of a material.

A molecular turnstile composed of a hydroquinone based rotor and a stator bearing a tridentate coordinating site can be reversibly switched between open and closed states. The locking and unlocking processes may be read optically.

An unprecedented mode of assembly of helical motives and Ag(I)  ions in the crystalline state is described. The combination of a Zn(II) helicate based on a 2,2'-bisdpm bearing peripheral benzonitrile moieties with AgX salts, leads to the formation of a tetranuclear core containing Ag-π interactions. Depending on the coordinating ability of the X(-) anion and the solvents used, the tetranuclear complex self-assembles into coordination polymers of varying dimensionality. From the sequence of coordination events (Ag-π or Ag-peripheral site), one may envisage two possible construction scenarios. However, the Ag-π as primary event seems reasonable owing to the rather weak binding propensity of the nitrile group and the chelating nature of the π-clefts., (Copyright © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

The use of compound 1 as an enantiomerically pure neutral and rigid organic linear tecton bearing two divergently oriented monodentate coordinating sites appended with two chiral centres of the same (S) configuration leads, in the presence of neutral metal complexes behaving either as a linear (Cu(hfac)2, Cu(OAc)2) or a V-shaped (HgCl2) 2-connecting node or a 4-connecting square node (NiCl2), to the formation of four homochiral 1- and 2-D coordination polymers.

The combination of the same organic tecton 1, a meta-pyridyl appended tetramercaptotetrathiacalix[4]arene in 1,3-alternate conformation offering four pyridyl units and eight thioether groups, with three silver salts AgX (X = BF4(-), NO3(-) and SbF6(-)) leads, under identical conditions (concentration, temperature and solvent system), to the formation of different silver coordination networks. Both the connectivity and the dimensionality of the three silver coordination networks depend on the nature of the anion used as a counter ion. Whereas the weakly coordinating BF4(-) anion does not participate in the formation of the non-tubular 1D coordination network, the coordinating NO3(-) anion is bound to the metal cation and this leads to the formation of a tubular 1D silver coordination network. In both cases, the eight S atoms of the tecton 1 do not take part in the binding of the cation. In marked contrast, when the SbF6(-) anion is used as a counter ion, the organic tecton 1 behaves as a tetrakismonodentate through its four meta-pyridyl moieties and as a bischelating unit of the SCCS type leading thus to the formation of a porous 3D diamondoid-type network.

A symmetrical organometallic Pt(II) based molecular turnstile 1, composed of a rotor bearing two benzonitrile units as coordinating sites and a stator equipped with a dianionic tridentate coordinating pole, undergoes a reversible switching process between two open and one closed states. In the absence of an effector, the turnstile is in its open state defined by the free rotation of the rotor around the stator. In the presence of Pd(II), the latter is simultaneously complexed by both the rotor and the stator (1-Pd) leading to the first closed state owing to locking of the rotational movement. The turnstile can be unlocked to its second open state 1-Pd-DMAP by addition of para-dimethylaminopyridine (DMAP) behaving as an external competitive ligand replacing the bound benzonitrile in the coordination sphere of the Pd centre. Upon addition of PdCl2(CH3CN)2, a competitive metal complex to remove DMAP, the turnstile is switched back to its closed state. The same process can also be achieved upon addition of MsOH causing the protonation of DMAP into DMAP-H(+) and its decomplexation and replacement by one of the two benzonitrile groups of the rotor. Finally, the deprotonation of DMAP-H(+) by addition of Et3N as a base regenerates the second open state of the turnstile.

Combinations of three enantiomerically pure organic chiral linear tectons bearing two divergently oriented pyridyl units as coordinating poles with HgCl2 as a two-connecting V-shape metallatecton offering two free coordination sites lead to the formation of stair-type 1D enantiomerically pure mercury coordination networks.

Both sequential and one-pot strategies for the preparation of a series of grid-type mixed metal-organic frameworks (MM'MOFs) based on dipyrrin ligands appended with either a pyridyl or a phenyl-imidazolyl moiety have been investigated. For the stepwise approach, the differentiation between the two coordination sites (nature, charge, and denticity) was exploited for the synthesis of a family of five discrete Zn(II), Cu(II), and Pd(II) complexes. Acting as metallatectons, these construction building blocks lead to the formation of a series of MM'MOFs upon self-assembly with CdCl2. In these rhombic grid-type architectures, four consecutive metallatectons are bridged by Cd(II) cations adopting an octahedral coordination geometry with the chloride anions occupying apical positions, thus behaving as square nodes. The shape of the rhombus grids as well as the way they are packed (stacking or interpenetration) in the crystalline phase are controlled by the nature of metallatectons and the solvent molecules present in the crystals. Consequently, the heterometallic assemblies display different accessible voids, although they are built on layers with the same connectivity. More interestingly, as demonstrated by X-ray diffraction on both single crystals and microcrystalline powders, the same MM'MOFs were obtained by a one-pot strategy through direct combinations of dipyrrin derivatives with the corresponding metal salts. This one-pot approach is efficient and more convenient than the sequential alternative, since the isolation, purification, and characterization of the, sometimes insoluble, metallatectons are not required.

The in situ combination of M(II) cations (Co, Ni, Cu or Zn) with 2,4,6-pyridinetricarboxylic acid as a ligand, a bisamidinium dication as a H-bond donor tecton and NaOH leads to the formation of anionic metal complexes ML2(2-) and their interconnection into isomorphous 3D H-bonded networks displaying different colours which were used as preformed seed crystals for the formation of crystals of crystals by 3D epitaxial growth.

Upon combining KCu(CN)2 with six different symmetrical dicationic bisamidinium moieties possessing different shapes and geometries, seven new coordination networks of the cyanocuprate type displaying 1-, 2- and 3-D dimensionality have been obtained. The formation of networks results from the interconnection of Cu(i) centres by cyanide anions through different bridging modes. The organic dicationic tectons interact with the anionic networks by charge-assisted H-bonds and, depending on their geometric features, they play different structuring roles. In the case of the 1D cyanocuprate networks, the organic cation interconnects consecutive anionic chains, increasing thus the overall dimensionality of the arrangement to 2D. For the 2D networks, either riveting or intercalation has been observed. For the riveting case, either the process takes place only between two consecutive sheets leading to a double layer type arrangement and thus without an increase of dimensionality, or between consecutive 2D networks in an alternate fashion. In the latter case, the dimensionality of the overall architecture is increased to 3 as for the intercalated case. For the 3D architectures, the dicationic moieties are located within the generated channels.

Three p-H-thiacalix[4]arene pyridyl appended coordinating tectons (2-4) in a 1,3-alternate conformation have been prepared and structurally characterised in the solid state. These compounds are positional isomers differing only by the position of the nitrogen atom on the pyridyl ring. Their combinations with HgCl2 lead to the formation of 1- and 2-D neutral mercury coordination networks. Whereas for tecton 2 (ortho isomer) a 2D architecture resulting from the bridging of consecutive tectons by the mononuclear HgCl2 unit is obtained, for tecton 3 (meta isomer) again a 2D network is formed. However, in that case, the interconnection of consecutive organic tectons 3 takes place through a binuclear Hg2Cl4 species. Finally, in the case of tecton 4 (para position), a 1D ribbon type double chain arrangement resulting from the bridging of consecutive tectons by trinuclear Hg3Cl6 units followed by the interconnection of two chains through the fusion of the trinuclear centres into a hexanuclear node is observed.

An organometallic molecular turnstile composed of a stator based on an α,ω-diphosphine bearing, in a symmetric fashion, the 2,6-pyridyl diamide moiety as a central tridentate chelating unit and a rotor composed of Pt(II) equipped with two pyridyl groups in trans configuration was designed. The switching between its open and closed states using Pd(II) was investigated both in solution and in the solid state.

Combinations of tetramercaptotetrathiacalix[4]arene pyridyl-appended positional isomers with HgCl2 lead to the formation of neutral coordination networks with their dimensionality imposed by the position of the N atom on the pyridyl group.

Upon combining enantiomerically pure bis-monodentate organic tectons with ZnSiF6, homochiral 3D cuboid architectures displaying chiral channels are formed.

The synthesis of an organometallic turnstile based on a Pt(II) centre as a hinge was achieved. Its dynamic behaviour in solution was investigated using 1D and 2D NMR techniques. Using Ag(I) cation as an effector, the switching between its open and closed states in solution was demonstrated.

A series of six isostructural heterometallic trinuclear oxalate-bridged complexes of the formula (TDbenz)(2)(TsO)(2)[M(II)(H(2)O)(2){(μ-ox)M(III)(ox)(2)}(2)]·6H(2)O·2CH(3)OH (TDbenz = 1,3,5-tris[2-(1,3-diazolinium)]benzene; TsO = 4-methylbenzenesulfonate; ox = oxalate; M(III) = Fe, M(II) = Mn (1), Fe (2), Co (3); M(III) = Cr, M(II) = Mn (4), Fe (5), Co (6)) have been synthesized from (NH(4))(3)[M(III)(ox)(3)]·3H(2)O, the chloride salts of the divalent metal ions and the tosylate salt of 1,3,5-tris[2-(1,3-diazolinium)]benzene (trisamidinium). Whereas the crystal structures of compounds 2, 3, 4 and 5 have been investigated by single-crystal X-ray diffraction, the structures of 1 and 6 have been checked by X-ray powder diffraction. All six compounds are isostructural and crystallise in the P1 space group. The crystals are composed of discrete linear [M(II)(H(2)O)(2){(μ-ox)M(III)(ox)(2)}(2)](4-) trinuclear bimetallic units, trisamidinium and tosylate ions and solvent molecules. The linear trinuclear unit is based on a central trans-diaquametal(II) entity connected to two [M(III)(ox)(3)](3-) (M(III) = Cr(III), Fe(III)) moieties through oxalate bridges. The divalent metal ions, surrounded by six oxygen atoms, adopt a distorted octahedral coordination geometry. The coordination sphere is composed of four oxygen atoms belonging to two oxalate ligands and two trans-coordinated water molecules. One of the oxalate ions is coordinated to the central metal centre whereas the other two oxalate ligands are non-bridging. In the crystal, intermolecular hydrogen bonds involving oxalate ligands, solvent molecules and the counter-ions form a complex 3D network. Variable-temperature magnetic susceptibility measurements indicate an antiferromagnetic interaction between the iron(III) and the metal(II) ions (J = -4.23, -6.73, -8.97 cm(-1) for 1, 2 and 3 respectively) whereas this interaction is ferromagnetic when iron(III) is replaced by chromium(III) (J = +1.21, +2.20, +3.63 cm(-1) for 4, 5 and 6 respectively). Moreover, the cobalt(II) derivatives exhibit high D values (D = 29.3 cm(-1) for and D = 27.4 cm(-1) for 6).

A series of novel Cd(II) complexes based on α,β-unsubstituted dipyrrin ligands (dpm) has been prepared and characterised both in solution and in the solid state. These compounds are of the [Cd(dpm)(2)] type, with the coordination sphere of the metal centre occupied by two dpm chelates. Interestingly, in contrast to what has been reported for the Zn(II) analogues, in the presence of a pyridyl- or imidazolyl-appended dpm ligand, the coordination number of the Cd(II) cation can be increased to six, leading to an octahedral coordination sphere. As a consequence, the formation of 1-, 2-, and 3D coordination polymers by self-assembly is observed. Photophysical investigations of the discrete complexes and self-assembled networks have demonstrated that both types of compounds are luminescent in the solid state., (Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)