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Molecular electronics is generally considered an alternative approach for the future fabrication of electronic devices. In the past few decades, benefiting from the impressive advancement in synthetic chemistry there emerged abundant molecular structures that are able to serve as conductive backbones for the electrons to transport through, as well as derivatives containing versatile substituents. Controlling the charge transport through a molecule lays the foundation for incorporating the molecule as a functional component in an active electronic device. In recent years the study on substituent-dependent conductance behavior attracted intensive research interest as it provides a feasible strategy to tune the electron transport in the molecule. In this review, we summarized the influence of substituents on single-molecule conductance and the mechanism of the influence into three aspects: the quantum interference effect, the electronic effect of substituents inducing changes in the energy levels of molecular orbitals, and the conformational restriction of the conductive backbone by the weak interaction between the substituents. [ABSTRACT FROM AUTHOR]

Mononuclear platinum(ii) complex trans-Pt(PPh3)2(C≡CC6H4SMe-4)2 (1-Pt) and its derivatives [PtM(dppm)2(C≡CC6H4SMe-4)2]+ (dppm = bis(diphenylphosphino)methane; M = Au, 2-PtAu; Ag, 2-PtAg; Cu, 2-PtCu) with “mono-gating” metal ions and [PtM2(dpmp)2(C≡CC6H4SMe-4)2]2+ (dppm = bis(diphenylphosphinomethyl)phenylphosphine; M = Au, 3-PtAu2; Ag, 3-PtAg2) with “dual-gating” metal ions were elaborately designed to modulate the conductance in platinum(ii) bis(σ-acetylide) complexes through “gating” d10 metal ions. The single-molecule conductance measurements by the STM-BJ technique demonstrate that the conductance follows 10−4.5 (1-Pt) ＞ 10−4.8 (2-PtAu) ＞ 10−4.9 (2-PtAg) ＞ 10−5.0 (2-PtCu) ＞ 10−5.1 (3-PtAu2) ＞ 10−5.3 (3-PtAg2) G0. Undoubtedly, charge transport along the platinum(ii) bis(σ-acetylide) backbone is progressively restricted by introducing one to two “gating” M ions to the mononuclear platinum(ii) molecule. As revealed by X-ray crystallography, the “gating” d10 metal ion is substantially bound to the acetylide and in fact the M–acetylide bonding is progressively enhanced in the order Au–Cacetylide→ Ag–Cacetylide→ Cu–Cacetylide, which coincides with a progressive decrease in the conductance as 10−4.8 (2-PtAu) ＞ 10−4.9 (2-PtAg) ＞ 10−5.0 (2-PtCu) G0. The M–acetylide coordination blocks the charge transport along the platinum(ii) bis(σ-acetylide) backbone so that the d10 metal ion behaves as a resistor to suppress the conductance. Theoretical studies confirm that the “gating” metal ions control the HOMO energy, which is lowered by the increased d orbital contribution of “gating” metal ions through Pt–M interactions. [ABSTRACT FROM AUTHOR]

Magnetocaloric effect (MCE) and thermal conductivity of two gadolinium hydroxides, Gd(OH)3 (1) and Gd2O(OH)4(H2O)2 (2), are investigated. Magnetic studies indicate that both 1 and 2 exhibit antiferromagnetic interaction, and the MCE values for 1 and 2 at 2 K and ΔH = 7 T are 62.00 J kg−1 K−1 and 59.09 J kg−1 K−1, respectively. Investigation of their thermal conductivity reveals that the thermal conductivity for 1 is significantly better than that for 2. [ABSTRACT FROM AUTHOR]

Magnetocaloric effect (MCE) and thermal conductivity of two gadolinium hydroxides, Gd(OH)3 (1) and Gd2O(OH)4(H2O)2 (2), are investigated. Magnetic studies indicate that both 1 and 2 exhibit antiferromagnetic interaction, and the MCE values for 1 and 2 at 2 K and ΔH = 7 T are 62.00 J kg−1 K−1 and 59.09 J kg−1 K−1, respectively. Investigation of their thermal conductivity reveals that the thermal conductivity for 1 is significantly better than that for 2. [ABSTRACT FROM AUTHOR]

Three heterometallic cluster complexes {Ln12Mo4} featuring an Ln12 core of a distorted truncated tetrahedron were synthesized with the assistance of four MoO42− anions as ancillary ligands. Magnetic studies of the {Gd12Mo4} cluster revealed a large magnetocaloric effect due to the presence of the large number of weakly coupled Gd(iii) ions. [ABSTRACT FROM AUTHOR]

Proton transport along different axes in an organic-inorganic compound [(C(6)H(10)N(2))(2)(SO(4))(2)·3H(2)O](n) (1) was investigated, revealing that proton transport is not only influenced by the structure of the proton transport pathway, but also by the order-disorder extent of proton carriers., (This journal is © The Royal Society of Chemistry 2012)