Mo- and W‑Based Organic Nanostructures Prepared from Bulk Crystal Isomorphs Consisted of [(CH₃CH₂)₃NH)]₂[MO₂(C₁₄H₆O₄)₂] (M = Mo, W)

Two new crystal isomorphs consisting of complexes [(CH₃CH₂)₃­NH)]₂­[MoO₂­(C₁₄H₆O₄)₂] (<b>1</b>) and [(CH₃CH₂)₃­NH)]₂­[WO₂­(C₁₄H₆O₄)₂] (<b>2</b>) have been synthesized, respectively, and from which Mo-based flexible and durable nanopipes with diameters of 16 nm and lengths of hundreds of micrometers and W-based rigid and fragile nanotubules with ununiform diameters ranging from 30 to 100 nm and lengths in tens of micrometers have been prepared separately, which revealed that the change of the metal in the coordination center of the isomorphs can result in obvious variation to their nanostructures. The crystals both exhibited multilayered structures by the piling of lamellar repeating motifs through van der Waals forces, which are formed by the parallel alignment of 1D chains through hydrogen bonds, and the 1D chains are assembled by complexes <b>1</b> and <b>2</b>, respectively, through geometrical intercalation and π–π packing. However, under grinding and ultrasonication, crystal <b>1</b> disassembled uniformly into longer and narrower nanostrips, whereas crystal <b>2</b> were broken at random into shorter and wider nanoribbons; therefore, the two lamellar nanostructures curled into different cylindrical nanospecies. The differences caused by Mo and W are the following: the Mo complex prefers to assemble into more durable one-dimensional structures along Mo–O bonds than W isomorphs; since Mo–O bonds are weaker than MoO and W–O bonds, then the weakest Mo–O bonds can be supported by the adjacent molecules through intercalation and π–π packing, which resulted in that the linkages among the Mo complexes are stronger along the Mo–O direction and hence the longer Mo-based cylindrical structure. Moreover, the flexibility of Mo-based nanopipes and the rigidity of W-based nanotubules might be attributed to that Mo possesses a lower melting point than W; therefore, Mo is softer and W is harsher

Mo- and W‑Based Organic Nanostructures Prepared from Bulk Crystal Isomorphs Consisted of [(CH₃CH₂)₃NH)]₂[MO₂(C₁₄H₆O₄)₂] (M = Mo, W)

Two new crystal isomorphs consisting of complexes [(CH₃CH₂)₃­NH)]₂­[MoO₂­(C₁₄H₆O₄)₂] (<b>1</b>) and [(CH₃CH₂)₃­NH)]₂­[WO₂­(C₁₄H₆O₄)₂] (<b>2</b>) have been synthesized, respectively, and from which Mo-based flexible and durable nanopipes with diameters of 16 nm and lengths of hundreds of micrometers and W-based rigid and fragile nanotubules with ununiform diameters ranging from 30 to 100 nm and lengths in tens of micrometers have been prepared separately, which revealed that the change of the metal in the coordination center of the isomorphs can result in obvious variation to their nanostructures. The crystals both exhibited multilayered structures by the piling of lamellar repeating motifs through van der Waals forces, which are formed by the parallel alignment of 1D chains through hydrogen bonds, and the 1D chains are assembled by complexes <b>1</b> and <b>2</b>, respectively, through geometrical intercalation and π–π packing. However, under grinding and ultrasonication, crystal <b>1</b> disassembled uniformly into longer and narrower nanostrips, whereas crystal <b>2</b> were broken at random into shorter and wider nanoribbons; therefore, the two lamellar nanostructures curled into different cylindrical nanospecies. The differences caused by Mo and W are the following: the Mo complex prefers to assemble into more durable one-dimensional structures along Mo–O bonds than W isomorphs; since Mo–O bonds are weaker than MoO and W–O bonds, then the weakest Mo–O bonds can be supported by the adjacent molecules through intercalation and π–π packing, which resulted in that the linkages among the Mo complexes are stronger along the Mo–O direction and hence the longer Mo-based cylindrical structure. Moreover, the flexibility of Mo-based nanopipes and the rigidity of W-based nanotubules might be attributed to that Mo possesses a lower melting point than W; therefore, Mo is softer and W is harsher

Improving and Fining of Nanostructures by Mixing W with Mo in Metal Organic Hybrid Crystal

A bialloy-like multilayered bulk single crystal consisting of [(CH₃CH₂)₃NH)]₂­[W_0.25Mo_0.75O₂­(C₁₄H₆O₄)₂] has been synthesized, from which Mo–W-mixed organic hybrid nanotubes with a diameter of about 50 nm and length from tens to hundreds of nanometers were prepared by grinding and ultrasonication. The nanotubes possess the uniformity of Mo-based nanopipes and the rigidity of W-based nanotubules and are more delicate and standardized than W-based nanotubules and shorter than Mo-based nanopipes. Furthermore, the Mo–W-mixed nanotubes are disassembled into Mo-based nanowires with a diameter of about 5 nm and lengths in tens of nanometers and W-based nanoparticles with a diameter of 6 nm, which are much finer than the nanoarchitectures produced from Mo- and W-based crystal isomorphs. This research offers two new methods: one is the improvement of nanostructures in physical properties and morphologies by bialloy-like treatment, and another is the refinement of nanostructures compared with those made from crystal isomorphs based on one kind of metal, by mixing metals in a crystal lattice