Polycyanometallate compounds with both photochromism and photomagnetism have appealing applications in optical switches and memories, but such optical behaviors were essentially restricted to the cryogenic temperature. We realized, for the first time, the photochromism and photomagnetism of 3d-4f hexacyanoferrates at room temperature (RT) in [Eu(III)(18C6)(H2O)3]Fe(III)(CN)6·2H2O (18C6 = 18-crown-6). Photoinduced electron transfer (PET) from crown to Fe(III) yields long-lived charge-separated species at RT in air in the solid state and also weakens the magnetic susceptibility significantly. The PET mechanism and changing trend of photomagnetism differ significantly from those reported for known 3d-4f hexacyanoferrates. This work not only develops a new type of inorganic-organic hybrid photochromic material but opens a new avenue for RT photomagnetic polycyanometallate compounds.

Obesity is a major risk factor for developing nonalcoholic fatty liver disease (NAFLD). NAFLD is the most common form of chronic liver disease and is closely associated with insulin resistance, ultimately leading to cirrhosis and hepatocellular carcinoma. However, knowledge of the intracellular regulators of obesity-linked fatty liver disease remains incomplete. Here we showed that hepatic Rho-kinase 1 (ROCK1) drives obesity-induced steatosis in mice through stimulation of de novo lipogenesis. Mice lacking ROCK1 in the liver were resistant to diet-induced obesity owing to increased energy expenditure and thermogenic gene expression. Constitutive expression of hepatic ROCK1 was sufficient to promote adiposity, insulin resistance, and hepatic lipid accumulation in mice fed a high-fat diet. Correspondingly, liver-specific ROCK1 deletion prevented the development of severe hepatic steatosis and reduced hyperglycemia in obese diabetic (ob/ob) mice. Of pathophysiological significance, hepatic ROCK1 was markedly upregulated in humans with fatty liver disease and correlated with risk factors clustering around NAFLD and insulin resistance. Mechanistically, we found that hepatic ROCK1 suppresses AMPK activity and a ROCK1/AMPK pathway is necessary to mediate cannabinoid-induced lipogenesis in the liver. Furthermore, treatment with metformin, the most widely used antidiabetes drug, reduced hepatic lipid accumulation by inactivating ROCK1, resulting in activation of AMPK downstream signaling. Taken together, our findings establish a ROCK1/AMPK signaling axis that regulates de novo lipogenesis, providing a unique target for treating obesity-related metabolic disorders such as NAFLD.

A series of inorganic-organic hybrid compounds L(2)(Bi(2)Cl(10)) (L = HMV(2+) = N-proton-N'-methyl-4,4'-bipyridinium for 1, L = HBzV(2+) = N-proton-N'-benzyl-4,4'-bipyridinium for 2, and L = HPeV(2+) = N-proton-N'-phenethyl-4,4'-bipyridinium for 3) have been successfully synthesized by an in situ solvothermal reaction. Compounds 1-3, with the same metal halide as anions but different asymmetric viologen molecules as cations, are ideal model compounds for investigating the detailed effect of different photochromically active molecules on the photochromic properties of the hybrids. Compound 1 shows no photochromic behavior, but compounds 2 and 3 possess photochromism and show a faster photoresponse rate than other reported viologen metal halide hybrids. Studies on the relationship between the structure and photochromic behavior clearly reveal that π-conjugated substituents could be used to improve the photoresponsibility and enrich the developed color efficiently and that the π···π interaction among organic components may not only be a powerful factor to stabilize the viologen monocation radical but also act as the second path of electron transfer from the π-conjugated substituent to the viologen cation for the photochromic process, which significantly influences the photochromic properties.