ABSTRACT
An extra-large octahedral coordination cage (CIAC-114) was designed and modeled based on Co4-p-tert-butylsulfonylcalix[4]arene (Co4-(SC4A-SO2)) subunits and 4,4',4''-(benzene-1,3,5-triyl-tris(benzene-4,1-diyl))tribenzoate (BBB) ligands via the isomorphic replacement approach built from an analogous cage structure with a smaller size. X-ray crystallography revealed that the crystals obtained through solvothermal synthesis exhibited the anticipated structure. Each CIAC-114 cage is assembled by six tetranuclear Co4-(SC4A-SO2) units as vertices, which bear a four-fold rotational symmetry, and eight tripodal BBB ligands as linkers, which hold a D3h symmetry. Among its analogues CIAC-114 has the largest overall peripheral diameter of 5.4 nm and an internal cavity of 2.7 nm. After treatment by supercritical CO2, a single crystal sample of CIAC-114 transformed into amorphous material with the retention of the cage skeleton, which demonstrated good adsorption properties towards a small drug molecule, ibuprofen (Ibu), evidenced by IR spectroscopy, (1)H NMR spectroscopy, N2 sorption analysis, and drug release experiments. The Ibu release experiment in phosphate buffered saline solution (pH = 7.4) revealed that CIAC-114 exhibited a slow drug release behavior.
Subject(s)
Anti-Inflammatory Agents, Non-Steroidal/chemistry , Calixarenes/chemistry , Drug Delivery Systems , Ibuprofen/chemistry , Models, Molecular , X-Ray Diffraction/methods , Crystallography, X-Ray , Ligands , Molecular StructureABSTRACT
Two nanoscale coordination cages based on M4-TC4A (M = Co(II) and Fe(II); H4TC4A = p-tert-butylthiacalix[4]arene) and 2,2'-bipyridine-4,4'-dicarboxylic acid (H2bpdc) have been synthesized and characterized. In these isostructural structures, there are two kinds of shuttlecock-like M4-TC4A secondary building units, {M4(TC4A)(Cl)} and {M4(TC4A)(SO4)}, which have different coordination environments and are bridged by bpdc molecules into an elongated octahedron through a [6 + 8] condensation. The gas sorption and magnetic properties were studied.
ABSTRACT
Two 2D metal-calixarene aggregates were designed and assembled by M4-TC4A (M = Fe, Co; TC4A = p-tert-butylthiacalix[4]arene) SBUs and {MCl2} units with isonicotinic acid molecules, which presents a possible way to build the extended metal-calixarene assemblies incorporating pre-designed nanocages using multifunctional linkers.
ABSTRACT
A novel coordination nanocage was obtained with in situ-generated tetrazole ligands from the cobalt-thiacalix[4]arene system. Four in situ-generated 1,3-bis(2H-tetrazol-5-yl)benzene ligands bolster eight Co4-calix shuttle-cock-like secondary building units (SBUs) into a hollow tetragonal prism with a high surface area. The unprecedented {Co32} nanocage presents the highest nuclearity example.
ABSTRACT
A strategy for building coordination cages by a [6 + 8] condensation of M(II)(4)-calix SBUs and rigid ancillary ligands was successfully applied to a cobalt-sulfonylcalix[4]arene system. A giant cage obtained with BTE ligands has an overall periphery diameter of 5.0 nm and an internal spherical cavity of 2.3 nm.
ABSTRACT
Two hybrid assemblies (3 and 4) with two kind of nanoscaled cluster units, the spherical [Co(24)(TC4A)(6)(MO(4))(8)Cl(6)](2+) cation (1 and 2) and Keggin-type [PM(12)O(40)](3-) anion (M = Mo (1/3), W (2/4)), were solvothermally prepared and characterized, in which the spherical units are constructed by six Co(4)-p-tert-butylthiacalix[4]arene (Co(4)-TC4A) SBUs linked by eight MO(4) tetrahedrons and present the highest nuclearity bimetallic clusters capped by cailxarenes.
Subject(s)
Cobalt/chemistry , Molybdenum/chemistry , Nanospheres/chemistry , Organometallic Compounds/chemistry , Phenols/chemistry , Tungsten/chemistry , Models, Molecular , Organometallic Compounds/chemical synthesis , TemperatureABSTRACT
A [Co(24)] metallamacrocycle with a [36-MC(Co)-12] periphery and an inner [24-MC(Co)-6] rim is constructed by linking six Co(4)-thiacalixarene shuttlecock-like SBUs with twelve 1,2,4-triazole molecules.
