Structural Transformation of Zn -Dipyridylamide-Based Coordination Frameworks: Hybrid-Ligand and Metal Effects.

A series of one-dimensional (1D) double-zigzag ({[Zn(papx) (H O) ](ClO ) } (x=so 1, sc 3, oc 5, and soc 7) and 2D polyrotaxane ([Zn(papx) (ClO ) ] (x=so 2, sc 4, oc 6, and soc 8) frameworks are synthesized by the reactions of Zn(ClO ) with equimolar amounts of papx (i.e., papso=1/2paps+1/2papo, papsc=1/2paps+1/2papc, papoc=1/2papo+1/2papc, and papsoc=1/3paps+1/3papo+1/3papc; paps=N,N'-bis(pyridylcarbonyl)-4,4'-diaminodiphenyl thioether, papo=N,N'-bis(pyridylcarbonyl)-4,4'-diaminodiphenyl ether, papc=N,N'-(methylenedi-p-phenylene)bispyridine-4-carboxamide).

Zn -Dipyridylamide-Based Coordination Frameworks: Structural Transformation and Anion Effect.

We have synthesized a series of 1 D double-zigzag ({[Zn(paps) (H O) ](PF ) }  (1), {[Zn(papo) (H O) ](PF ) }  (3), and {[Zn(papc) (H O) ](PF ) }  (5)) and 2 D polyrotaxane ([Zn(papc) (PF ) ]  (6)) frameworks through the reaction of Zn(PF ) with dipyridylamide ligands (N,N'-bis(pyridylcarbonyl)-4,4'-diaminodiphenyl thioether (paps), N,N'-bis(pyridylcarbonyl)-4,4'-diaminodiphenyl ether (papo), and N,N'-(methylenedi-p-phenylene)bispyridine-4-carboxamide (papc), respectively), and their molecular structures have been determined through X-ray diffraction studies. From the powder X-ray diffraction (PXRD) experiments, it is found that on heating, the double-zigzag frameworks 1 and 3 undergo structural transformation to give the respective polyrotaxane frameworks 2 ([Zn(paps) (PF ) ] ) and 4 ([Zn(papo) (PF ) ] ), which matched well with those of their Zn(ClO ) analogues. Furthermore, grinding the solid samples of 2 and 4 in the presence of moisture resulted in total conversion back to the double-zigzag frameworks 1 and 3, respectively.

Reversible phase transformation and luminescence of cadmium(II)-dipyridylamide-based coordination frameworks.

We have synthesized a series of 1D double-zigzag ({[Cd(paps)(2)(H(2)O)(2)](ClO(4))(2)}(n) (1), {[Cd(papo)(2)(H(2)O)(2)](ClO(4))(2)}(n) (3), and {[Cd(papc)(2)(H(2)O)(2)](ClO(4))(2)}(n) (5)) and 2D polyrotaxane frameworks ([Cd(papc)(2)(ClO(4))(2)](n) (6)) by the reaction of Cd(ClO(4))(2) with dipyridylamide ligands N,N'-bis(pyridylcarbonyl)-4,4'-diaminodiphenyl thioether (paps), N,N'-bis(pyridylcarbonyl)-4,4'-diaminodiphenyl ether (papo), and N,N'-(methylenedi-p-phenylene)bispyridine-4-carboxamide (papc), respectively, where their molecular structures have been determined by X-ray diffraction studies. Based on the powder X-ray data (PXRD) of compound 3 and its Zn(II) analogue, heating the double-zigzag framework of compound 3 can give the polyrotaxane framework of [Cd(papo)(2)(ClO(4))(2)](n) (4) and grinding this powder sample in the presence of moisture resulted in its complete conversion back into the pure double-zigzag framework. In addition, heating the double-zigzag frameworks of compounds 1 and 5 can induce structural transformation into their respective polyrotaxanes, whereas grinding these solid samples in the presence of moisture did not lead to the formation of the double zigzags.

Reversible phase transformation and mechanochromic luminescence of Zn(II)-dipyridylamide-based coordination frameworks.

A 1D double-zigzag framework, {[Zn(paps)(2)(H(2)O)(2)](ClO(4))(2)}(n) (1; paps = N,N'-bis(pyridylcarbonyl)-4,4'-diaminodiphenyl thioether), was synthesized by the reaction of Zn(ClO(4))(2) with paps. However, a similar reaction, except that dry solvents were used, led to the formation of a novel 2D polyrotaxane framework, [Zn(paps)(2)(ClO(4))(2)](n) (2). This difference relies on the fact that water coordinates to the Zn(II) ion in 1, but ClO(4)(-) ion coordination is found in 2.