Hydrothermal reaction of zinc nitrate, 4-(4-carboxyphenoxy)phthalate acid (H 3 cpop), and different N-donor coligands has afforded six novel supramolecular compounds, in which the nature of the neutral coligands plays a crucial structuredirecting role. [Zn(Hcpop)(H 2 O) 3 ] n (1) and [Zn(Hcpop)(phen)(H 2 O)] n (2, phen = 1,10-phenanthroline) form threedimensional (3D) supramolecular frameworks linked by H-bonds and π−π interactions based on discrete molecules. Similarly, [Zn 2 (Hcpop) 2 (4,4′-bpy) 3 (H 2 O) 2 ] n •4nH 2 O (3) possesses a 3D supramolecular structure, aggregated by interesting one-dimensional (1D) armed-polyrotaxane chains. [Zn 6 (cpop) 4 (4,4′-bpy) 2 (H 2 O) 2 ] n (4, 4,4′-bpy = 4,4′-bipyridine) exhibits a complicated 3Dframework, which can be rationalized as a (3,6,6)-connected trinodal net with a unique (4.6 2 ) 2 (4 2 .6 9 .8 3 .10)(4 4 .6 8 .8 3 ) topology.[Zn 3 (cpop) 2 (bpdb)(H 2 O) 2 ] n (5, bpdb = 1,4-bis(4-pyridyl)-2,3-diaza-1,3-butadiene) is a 3D structure containing twodimensional (2D) metal−carboxylate layers motifs, which are further pillared by cpop 3− and bpdb ligands to complete the structure. [Zn 6 (cpop) 4 (azpy) 2 (H 2 O) 4 ] n (6, azpy = 4,4′-azopyridine) manifests a unique quadruple layer structure constructed from two types of bilayered architectures linked by Zn 2+ ions and bridging azpy ligands. Meanwhile, solid-state properties such as thermal stability and the photoluminescence properties at room temperature for these complexes have also been systematically investigated.

The very first nanofluidic memristor based on the principle of ion concentration polarization (ICP).

Non-invasive and real-time imaging of the gastrointestinal (GI) tract is particularly desirable for research and clinical studies of patients with symptoms arising from gastrointestinal diseases. Here, we designed and fabricated silica-coated bismuth sulfide nanorods (Bi2S3@SiO2 NRs) for a non-invasive spatial-temporally imaging of the GI tract. The Bi2S3 NRs were synthesized by a facile solvothermal method and then coated with a SiO2 layer to improve their biocompatibility and stability in the harsh environments of the GI tract, such as the stomach and the small intestine. Due to their strong X-ray- and near infrared-absorption abilities, we demonstrate that, following oral administration in mice, the Bi2S3@SiO2 NRs can be used as a dual-modal contrast agent for the real-time and non-invasive visualization of NRs distribution and the GI tract via both X-ray computed tomography (CT) and photoacoustic tomography (PAT) techniques. Importantly, integration of PAT with CT provides complementary information on anatomical details with high spatial resolution. In addition, we use Caenorhabditis Elegans (C. Elegans) as a simple model organism to investigate the biological response of Bi2S3@SiO2 NRs by oral administration. The results indicate that these NRs can pass through the GI tract of C. Elegans without inducing notable toxicological effects. The above results suggest that Bi2S3@SiO2 NRs pave an alternative way for the fabrication of multi-modal contrast agents which integrate CT and PAT modalities for a direct and non-invasive visualization of the GI tract with low toxicity.