A cytotoxic bisindole alkaloid possessing an unprecedented structure in which two indole moieties are bridged by an aromatic spacer unit has been isolated from Alstonia angustifolia. The structure was established by analysis of the spectroscopic data and confirmed by X-ray diffraction analysis. A possible biogenetic pathway from pyrocatechuic acid and pleiocarpamine is presented.

A family of heteronuclear metal organic frameworks (MOFs) using lanthanide and transition metal ion based on a rigid ligand of substituted imidazoledicarboxylic acid, namely, {[Ln2Zn2 (μ3-Hmimda)2 (μ3-mimda)2·4H2O]n·mn H2O}, Ln = Nd, m = 2 (1), Ln = Ho, m = 3 (2), Ln = Er, m = 2 (3), Ln = Yb, m = 3 (4), [Tb2Co2(μ3-Hmimda)2 (μ3-mimda)2·4H2O]n·2nH2O} (5) and [Dy2Co2 (μ3-Hmimda)2 (μ3-mimda)2·4H2O]n·nH2O} (6), (H3mimda = 1H-2-methyl-4,5-imidazole-dicarboxylic acid), have been developed and characterized. All the complexes (except for a little disparity for 1) are isostructural, and all crystallize in the monoclinic system. They possess an extended reticular-like porous structure constructed from corrugated 2D layers. Direct current (dc) magnetic susceptibility measurements for 1-5 indicated depopulation of the Stark components at low temperature and/or possible weak anti-ferromagnetic interactions within hetero-nuclear MOFs. Alternating current (ac) susceptibility studies reveal that the Dy(III)-Co(II) complex exhibits both possible ferromagnetic couplings and frequency-dependent out-of-phase signals, behaviour of single-ion magnet nature. Fluorescence properties of series complexes both in near-infrared (NIR) and visible regions have been comparatively studied.

Porous pillared bilayer open coordination polymer {[Cd(bpp) 2 (O 3 SFcSO 3 )] • (CH 3 OH) 2 • (H 2 O) 6 } n 1 (Fc ) ferrocene) and 3D porous coordination polymer {[Cd(bpy) 2 (O 3 SFcSO 3 )] • (CH 3 OH) 4 } n 2 have been assembled from Cd(NO 3 ) 2 , ferrocene-1,1′disulfonate, and bridging ligands 1,3-bis(4-pyridyl)propane (bpp) or 4,4′-bipyridine (bpy). Both of them show very special adsorption properties to copper salts. Along with the increase in the solution concentration of Cu(NO 3 ) 2 , the percentage of adsorbed copper ions falls, but the percentage of exchanged central cadmium ions and the amount of adsorbed copper ions rises. In dilute solution, there mainly exists metal ion sorption, whereas both ion sorption and exchange are in charge of the whole progress in strong solution. Meanwhile, such materials could be used as ideal metal ion adsorbent toward some other metal cations, including of Pb 2+ , Zn 2+ , Mn 2+ , Co 2+ , Ni 2+ . However, when all these metal ions coexist in a mixture solution, the two ferrocenyl complexes selectively adsorb large amounts of only Pb 2+ (for 1, 88.54%; for 2, 75.80%) and Cu 2+ (for 1, 90.94%; for 2, 79.45%). Ion sorption and central cadmium ion exchange might be considered as being dominated by the coordination ability of metal ions to free functional groups, ionic radii of adsorbed metal ions, and the solution concentration of adsorbed metal salts. On the basis of the recognition of ion exchange, the center metal ion-exchange product of 2, {[Cd 0.5 Cu 0.5 (bpy) 2 (O 3 SFcSO 3 )] • (CH 3 OH) 4 } n 3, could be obtained by ionexchange-induced single crystal to single crystal transformation.