Two benzothienobenzothiophene (BTBT)-based conjugated oligomers, i.e., 2,2′-bi[1]benzothieno[3,2-b][1]benzothiophene (1) and 5,5′-bis([1]benzothieno[3,2-b][1]benzothiophen-2-yl)-2,2′-bithiophene (2), were prepared and characterized. Both oligomers exhibit excellent thermal stability, with 5% weight-loss temperatures (TL) above 370 °C; no phase transition was observed before decomposition. The highest occupied molecular orbital (HOMO) levels of 1 and 2 are −5.3 and −4.9 eV, respectively, as measured by ultraviolet photoelectron spectroscopy. Thin-film X-ray diffraction and atomic force microscopy characterizations indicate that both oligomers form highly crystalline films with large domain sizes on octadecyltrimethoxysilane-modified substrates. Organic thin-film transistors with top-contact and bottom-gate geometry based on 1 and 2 exhibited mobilities up to 2.12 cm2/V·s for 1 and 1.39 cm2/V·s for 2 in an ambient atmosphere. 1-based devices exhibited great air and thermal stabilities, as evidenced by the slight performance degradation after 2 months of storage under ambient conditions and after thermal annealing at temperatures below 250 °C.Keywords: benzothienobenzothiophene; conjugated oligomers; field-effect mobility; organic semiconductors; organic thin-film transistors;

Although it is difficult to obtain LiFePO4/C particles with diameter less than 100 nm via solid state reaction, a simple, low cost and easily scaled-up method assisted by polyvinylpyrrolidone (PVP) was developed for mass production of nano-LiFePO4/C composites with average diameter of 80 nm in this study. Moreover, a homogeneous carbon layer (about 2 nm) was successfully coated on nano-LiFePO4 particle surface, which was difficult without PVP assistance. The combination of nano size and uniform carbon coating is important for the improvement of LiFePO4 electrochemical performance, especially the performance at low temperature. As a result, the obtained nano-LiFePO4/C composite possessed high discharge capacity of 160 mAh g−1 at 0.1 C. The capacity retention of the composite was kept over 120 mAh g−1 even at low temperature of −20 °C with the discharge rate of 0.1 C. In addition, the nano-LiFePO4/C composite showed excellent low temperature cycling performance with less than 3% capacity fading after 500 cycles at 0.6 C. The nano-sized cathode material via such simple method is beneficial for the application in electric vehicles as well as hybrid electric vehicles.A simple, low cost and easily scaled-up method assisted by polyvinylpyrrolidone (PVP) was developed for mass production of nano-LiFePO4/C composites with average diameter of 80 nm with good electrochemical performance especially at low temperature.

Four novel CuII complexes {Na[Cu4(hmp)4(CHOO)3](ClO4)2·H2O}n (1), [Cu8(hmp)8(CH3COO)6](ClO4)2 (2), [Cu4(hmp)4(CH3CN)2(ClO4)2(H2O)2](ClO4)2 (3), and [Cu4(hmp)4(CH3COO)2(H2O)4](ClO4)2·2H2O (4) with Hhmp = 2-(hydroxymethyl)pyridine were prepared by structural modulation at room temperature. Taking advantage of the steric hindrance of the ancillary ligands, the 1D copper chain (1) is successfully cut down into the octa-nuclear copper cluster (2) with the unchanged antiferromagnetic [Cu4O4] open-cubane that is further separated into weak antiferromagnetic [Cu4O4] (3) and then modulated to be the ferromagnetic tetra-nuclear [Cu4O4] cluster (4). The obtained four complexes allow us to systematically investigate their magnetic properties and find the rules for further magnetic investigations. The results showed that there exist antiferromagnetic interactions between Cu(II) ions in 1–3, while 4 displays ferromagnetic behaviour. The best fitting results to the experimental magnetic susceptibilities gave J1 = J2 = J3 = −2.26 cm−1, g = 2.11 for 3 and J1 = 37.05 cm−1, J2 = −0.62 cm−1, J3 = −0.62 cm−1, g = 2.13 for 4.

A series of 2,3,4-trisubstituted and 1,2,3,4-tetrasubstituted pyrroles were synthesized via [3+2] cycloaddition of α-acyl ketene dithioacetals (or related substrates) with commercially available propargylamines as 1,3-dipoles in water. Most of the reactions can be performed in the absence of an external base. The reaction of secondary amine (N-methylprop-2-yn-1-amine) with α-acyl ketene dithioacetals showed different reaction behaviours depending on the addition or absence of an external base.A series of 2,3,4-trisubstituted and 1,2,3,4-tetrasubstituted pyrroles were synthesized via [3+2] cycloaddition of α-acyl ketene dithioacetals (or related substrates) with commercially available propargylamines as 1,3-dipoles in water. Most of the reactions can be performed in the absence of an external base. The reaction of secondary amine (N-methylprop-2-yn-1-amine) with α-acyl ketene dithioacetals showed different reaction behaviours depending on the addition or absence of an external base.

gem-Dialkylthio vinylallenes were obtained for the first time and applied to the divergent synthesis of fully-substituted pyrroles and thiophenes by domino cyclizations. These two cyclization pathways were regulated by alkylthio groups. Plausible reaction mechanisms were presented and supported by DFT calculations. An unprecedented metal-free carbothiolation was discovered in the formation of thiophenes.

Microporous organic molecular crystals (MOMCs) are materials composed of discrete organic molecules interacting noncovalently. The gas uptake of CO2, CH4, N2, and Xe in one of the most widely investigated MOMCs, trispiro(benzodioxole[2′.2:2″.4:2‴.6]1,3,5,2,4,6-triazatriphosphinine) (1), was computed by grand canonical Monte Carlo (GCMC) simulations based on our lately developed force field method vdW3, which is fitted to accurate ab initio potentials (double hybrid functional B2PLYP with a D3 dispersion correction using def2-TZVPP basis sets). The B2PLYP-D3 results compare very well with CCSD(T)/CBS interaction energies for benzene–gas model complexes. Our multiscale modeling approach to accurate interaction potentials is found to be essential in order to obtain reasonable adsorption isotherms and heats of adsorption. The good agreement between the simulation results and experimental data in all cases gives us the opportunity to design novel complex materials for gas adsorption based solely on first-principles calculations.

The manganese phosphate with high P–O–Mn connectivity shows a two-step relaxation process in two distinct spin glass states.

Two complexes {[CoII(phen)3][CoIII(phen)(CN)4]2}·phen·11H2O (1) and [CoII(μ-CN)2(CoIII)2(phen)4(CN)6]·C2H5OH·2H2O (2) were synthesized with identical starting materials but with a different order of addition. Their crystal structures, spectroscopic analysis, DFT calculations, and investigations of their magnetic properties are reported herein. The X-ray diffraction studies reveal that complex 1 mainly consists of discrete [CoII(phen)3]2+ cations and [CoIII(phen)(CN)4]− anions, while complex 2 is dominantly comprised of discrete neutral V-shaped trinuclear units [CoII(μ-CN)2(CoIII)2(phen)4(CN)6]. The first low-spin CoII fragment with homoleptic 1,10-phenanthroline ligands in 1 is observed at room temperature, owing to charge transfer from the neighboring anion via adventitious contacts and anion–π interactions. This is verified by structures, detailed theoretical analyses concerning frontier molecular orbital energy differences and Mulliken charge variations of the N atoms within the CoIIN6 sphere, and magnetism. Meanwhile, these kinds of supramolecular interactions are not found in complex 2, so it shows the ordinary magnetic behavior of the high-spin CoII ion. Our investigations highlight that for quantitative comprehension of spin-state energetic ordering in transition metal complexes, the supramolecular interactions must be taken into account in addition to classical ligand field theory. Moreover, we find that the [CoII(phen)3]2+ dication is sensitive to its surroundings in the solid state, which is beneficial for magnetic adjustment for the further synthesis of tunable molecular magnets and spin crossover systems.

Herein, we report the first incorporation of 8-hydroxyquinoline ions into hetero- and homometallic one dimensional complexes [FeIIMnII(8-quinolinato)4·(H2O)0.25]n (1) and [MnII(8-quinolinato)2]n (2). Magnetic analyses of both complexes indicate antiferromagnetic interactions between the magnetic centers.

A novel asymmetric tetrathiafulvalene (TTF) derivative bearing a conjugated phenyl β-diketone moiety 1-(4-tetrathiafulvalyphenyl)-4,4,4-trifluorobutane-1,3-dione (TTF-ph-tfacH) has been synthesized using feasible methods and fully characterized. The chelating ability of its enolate anion (TTF-ph-tfac) has been investigated with [MIICl2·xH2O] (M = Zn and Co) leading to complexes [Zn(TTF-ph-tfac)2(CH3OH)2] (2a) and [Co(TTF-ph-tfac)2(CH3OH)2] (2b), where the metal center is coordinated with two TTF-ph-tfac ligands and two methanol molecules. This redox active ligand shows promising features for the elaboration of hybrid organic–inorganic building blocks. The magnetic analysis for 2b reveals very weak antiferromagnetic interactions between spin centers, which would be a precursor for magnetic conductors. The herein reported mono-substituted TTF derivative interconnected via the phenyl group, which is of extended conjugation, enhanced planarity, and asymmetric geometry, shows a great promise to multifunctional (conducting, non-linear optical, and magnetic) materials.

Two new solvent free complexes α-Feq3 (1) and α-Crq3 (2) have been synthesised under the hydrothermal reaction. Complex 1 with one dimensional void channels only consists of fac-Feq3 and crystallizes in the trigonal P3¯ space group. Complex 2 possessing the phase transition ability is composed of mer-Crq3, which crystallizes in the triclinic P1¯ space group. The detail magnetic studies accompanying with DFT investigations for the first time demonstrate the correlation between supramolecular assembly and magnetism among the Mq3 complexes that the larger the overlaps with the same signs of spin densities on stacking ligands, the more negative the value of the Weiss constant. Our investigations highlight that the spin density should be the dominant factor in analyzing the intermolecular magnetic interactions, which was rather difficult to figure out.Graphical abstractThe correlation between assembly structures and the bulk magnetism: the lager the overlap with the same sign spin densities on stacking ligands, the more negative the value of the Weiss constant (θ).Research highlights► Crystallography, magnetism, and DFT study of solvent free Feq3 (1) and Crq3 (2). ► 1D void channels exist in complex 1 with the potential for selective absorption. ► DFT studies show a clear correlation between assembly structures and bulk magnetism.

gem-Dialkylthio vinylallenes were obtained for the first time and applied to the divergent synthesis of fully-substituted pyrroles and thiophenes by domino cyclizations. These two cyclization pathways were regulated by alkylthio groups. Plausible reaction mechanisms were presented and supported by DFT calculations. An unprecedented metal-free carbothiolation was discovered in the formation of thiophenes.

The manganese phosphate with high P–O–Mn connectivity shows a two-step relaxation process in two distinct spin glass states.

Four novel CuII complexes {Na[Cu4(hmp)4(CHOO)3](ClO4)2·H2O}n (1), [Cu8(hmp)8(CH3COO)6](ClO4)2 (2), [Cu4(hmp)4(CH3CN)2(ClO4)2(H2O)2](ClO4)2 (3), and [Cu4(hmp)4(CH3COO)2(H2O)4](ClO4)2·2H2O (4) with Hhmp = 2-(hydroxymethyl)pyridine were prepared by structural modulation at room temperature. Taking advantage of the steric hindrance of the ancillary ligands, the 1D copper chain (1) is successfully cut down into the octa-nuclear copper cluster (2) with the unchanged antiferromagnetic [Cu4O4] open-cubane that is further separated into weak antiferromagnetic [Cu4O4] (3) and then modulated to be the ferromagnetic tetra-nuclear [Cu4O4] cluster (4). The obtained four complexes allow us to systematically investigate their magnetic properties and find the rules for further magnetic investigations. The results showed that there exist antiferromagnetic interactions between Cu(II) ions in 1–3, while 4 displays ferromagnetic behaviour. The best fitting results to the experimental magnetic susceptibilities gave J1 = J2 = J3 = −2.26 cm−1, g = 2.11 for 3 and J1 = 37.05 cm−1, J2 = −0.62 cm−1, J3 = −0.62 cm−1, g = 2.13 for 4.

Two complexes {[CoII(phen)3][CoIII(phen)(CN)4]2}·phen·11H2O (1) and [CoII(μ-CN)2(CoIII)2(phen)4(CN)6]·C2H5OH·2H2O (2) were synthesized with identical starting materials but with a different order of addition. Their crystal structures, spectroscopic analysis, DFT calculations, and investigations of their magnetic properties are reported herein. The X-ray diffraction studies reveal that complex 1 mainly consists of discrete [CoII(phen)3]2+ cations and [CoIII(phen)(CN)4]− anions, while complex 2 is dominantly comprised of discrete neutral V-shaped trinuclear units [CoII(μ-CN)2(CoIII)2(phen)4(CN)6]. The first low-spin CoII fragment with homoleptic 1,10-phenanthroline ligands in 1 is observed at room temperature, owing to charge transfer from the neighboring anion via adventitious contacts and anion–π interactions. This is verified by structures, detailed theoretical analyses concerning frontier molecular orbital energy differences and Mulliken charge variations of the N atoms within the CoIIN6 sphere, and magnetism. Meanwhile, these kinds of supramolecular interactions are not found in complex 2, so it shows the ordinary magnetic behavior of the high-spin CoII ion. Our investigations highlight that for quantitative comprehension of spin-state energetic ordering in transition metal complexes, the supramolecular interactions must be taken into account in addition to classical ligand field theory. Moreover, we find that the [CoII(phen)3]2+ dication is sensitive to its surroundings in the solid state, which is beneficial for magnetic adjustment for the further synthesis of tunable molecular magnets and spin crossover systems.