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The circadian clock orchestrates many physiological and behavioural rhythms in mammals with 24‐h periodicity, through a hierarchical organisation, with the central clock located in the suprachiasmatic nucleus (SCN) in the hypothalamus. The circuits of the SCN generate circadian rhythms with precision, relying on intrinsic coupling mechanisms, for example, neurotransmitters like arginine vasopressin (AVP), vasoactive intestinal peptide (VIP), neuronal gamma‐aminobutyric acid (GABA) signalling and astrocytes connected by gap junctions composed of connexins (Cx). In female rodents, the presence of estrogen receptors (ERs) in the dorsal SCN suggests an influence of estrogen (E2) on the circuit timekeeping that could regulate circadian rhythm and coupling. To investigate this, we used SCN explants together with hypothalamic neurons and astrocytes. First, we showed that E2 stabilised the circadian amplitude in the SCN when rAVPs (receptor‐associated vasopressin peptides) were inhibited. However, the phase delay induced by VIPAC2 (VIP receptors) inhibition remained unaffected by E2. We then showed that E2 exerted its effects in the SCN via ERβ (estrogen receptor beta), resulting in increased expression of Cx36 and Cx43. Notably, specific inhibition of both connexins resulted in a significant reduction in circadian amplitude within the SCN. Remarkably, E2 restored the period with inhibited Cx36 but not with Cx43 inhibition. This implies that the network between astrocytes and neurons, responsible for coupling in the SCN, can be reinforced through E2. In conclusion, these findings provide new insights into how E2 regulates circadian rhythms ex vivo in an ERβ‐dependent manner, underscoring its crucial role in fortifying the SCN's rhythm. [ABSTRACT FROM AUTHOR]

An enlarged version of the ubiquitous tetrathiafulvalene-tetrabenzoic acid is described, with 4,4′-biphenyl moieties as spacers between the coordination moieties and the electroactive core. The obtained rectangular ligand has a 14 × 22 Å2 size and is combined with Zn(II) under solvothermal conditions to yield a coordination polymer endowed with large cavities of ca. 15 × 11 Å2/10 × 10 Å2. The topology of the material is discussed in detail using the Points of Extension and Metals (PE&M) or the Straight-rod (STR) representation, and the sqc1121 or tfo topological type of the structure is observed, respectively. Its stability towards solvent removal and electrical properties are discussed. The material does not present any permanent porosity upon desolvation according to nitrogen sorption measurements at 77 K. Nevertheless, a significant increase in conductivity is observed on compressed pellets of the material upon post-synthetic oxidation with iodine. Raman spectroscopy combined with density functional theory (DFT) calculations has been used to characterize the oxidation state of tetrakis(4-carboxylic acid biphenyl)tetrathiafulvalene for coordination polymers. [ABSTRACT FROM AUTHOR]

Novel coordination polymers embedding electroactive moieties present a high interest in the development of porous conducting materials. While tetrathiafulvalene (TTF) based metal‐organic frameworks were reported to yield through‐space conducting frameworks, the use of S‐enriched scaffolds remains elusive in this field. Herein is reported the employment of bis(vinylenedithio)‐tetrathiafulvalene (BVDT‐TTF) functionalized with pyridine coordinating moieties in coordination polymers. Its combination with various transition metals yielded four isostructural networks, whose conductivity increased upon chemical oxidation with iodine. The oxidation was confirmed in a single‐crystal to single‐crystal X‐ray diffraction experiment for the Cd(II) coordination polymer. Raman spectroscopy measurements and DFT calculations confirmed the oxidation state of the bulk materials, and band structure calculations assessed the ground state as an electronically localized antiferromagnetic state, while the conduction occurs in a 2D manner. These results are shedding light to comprehend how to improve through‐space conductivity thanks to sulfur enriched ligands. [ABSTRACT FROM AUTHOR]

Electrocrystallization of TMTTF (tetramethyltetrathiafulvalene) in the presence of the dianionic [Pt(qS)2]2− platinum complex (qS: 5-sulfo-8-quinolinol) afforded simultaneously two phases. Phase A with isolated dicationic (TMTTF)22+ species is fully insulating and characterized by C–H hydrogen bonds with the anionic sulfonate moieties. Phase B is a mixed valence salt formulated as (TMTTF)3[Pt(qS)2]. It is organized into strongly trimerized chains, with a notably higher conductivity (σRT = 4 × 10−5 S cm−1). The charge distribution within the TMTTF trimers has been evaluated from the intramolecular bond distances, and IR and Raman spectra, converging all to a +0.5/+1/+0.5 motif, which is not modified at lower temperatures. Spectroscopic studies of such trimeric structures are scarce and the doublet (or triplet) structure expected in the IR of trimers is clearly identified here in the EMV-activated ν8(ag) mode associated with the totally symmetric vibration of methyl groups, in relation to the weak C–H⋯O hydrogen bonds between the radical cation and the dianionic [Pt(qS)2]2− platinum complex. [ABSTRACT FROM AUTHOR]

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