Three different N,N′-donor ligands with Zn(NO₃)₂·6H₂O and two different dicarboxylates, flexible succinate (suc) and rigid fumarate (fum) afforded six different metal–organic frameworks (MOFs). Among the N,N′-donor ligands, one bent 1,4-bis(3-pyridyl)-2,3-diaza-1,3-butadiene (3-bpdb) gives two isostructural two-dimensional MOFs, {[Zn(3-bpdb)(suc)]·(H₂O)₂}_n (1) and {[Zn(3-bpdb)(fum)(H₂O)₂]}_n (2). The use of a straight N,N′-donor ligand, i.e., 1,4-bis(4-pyridyl)-2,3-diaza-1,3-butadiene (4-bpdb), results in two three-dimensional (3D) MOFs, {[Zn₄(4-bpdb)₂(suc)₃(OH)₂]·5(H₂O)}_n (3) and {[Zn(4-bpdb)(fum)]·(H₂O)₂}_n (4). Here, 3 is a pillared layer structure, whereas 4 has a 5-fold interpenetrated dimondoid network. For both the bent and straight N,N′-donor ligands an imine alike motif is embedded in the structure. When this motif is replaced by a C–C double bond by using the ligand 1,2-bis(4-pyridyl)ethylene (bpee), it produces two MOFs, {[Zn(bpee)(suc)]₂·(H₂O)₃}_n (5) and {[Zn₂(bpee)₂(fum)₂]·(H₂O)}_n (6), having a similar structural relation like 3 and 4 respectively, 5 with a pillared layer structure and 6 with a 5-fold interpenetrated diamondoid network. All the compounds have been thoroughly characterized by powder X-ray diffraction (PXRD), elemental analysis, infrared (IR) spectroscopy, UV–vis spectroscopy, and thermogravimetric analyses. Gas/solvent vapor sorption studies have been carried out for compounds 3–6, which have 3D structures. In the case of 3, an interesting reversible crystalline to crystalline transformation was observed which has been thoroughly studied by PXRD analysis, IR spectroscopy, and UV–vis spectroscopy. Solid state emission spectral analysis for all the complexes was performed at room temperature.

中文翻译：

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刚性和柔性二羧酸盐以及不同的N，N'供体配体构成的六个混合配体Zn（II）金属-有机骨架的结构多样性

具有Zn（NO ₃）₂ ·6H ₂ O的三种不同的N，N'-供体配体和两种不同的二羧酸盐，柔性琥珀酸酯（suc）和刚性富马酸酯（fum）提供了六个不同的金属-有机骨架（MOF）。在N，N'-供体配体中，一个弯曲的1,4-双（3-吡啶基）-2,3-二氮杂-1,3-丁二烯（3-bpdb）给出两个同构的二维MOF，{[Zn （3-bpdb）（suc）]·（H ₂ O）₂ } _n（1）和{[Zn（3-bpdb）（fum）（H ₂ O）₂ ]} _n（2）。使用直接的N，N'-供体配体，即1,4-双（4-吡啶基）-2,3-二氮杂-1,3-丁二烯（4-bpdb），可得到两个三维（ 3D）MOF，{[Zn ₄（4-bpdb）₂（suc）₃（OH）₂ ]·5（H ₂ O）} _n（3）和{[Zn（4-bpdb）（fum）]·（H ₂ O）₂ } _n（4）。在此，3是柱状层结构，而4具有5倍互穿的二链体网络。对于弯曲的和笔直的N，N'-供体配体，亚胺类似的基序被嵌入结构中。当通过使用配体1,2-双（4-吡啶基）乙烯（bpee）将这个基序替换为C–C双键时，它会产生两个MOF，{[Zn（bpee）（suc）] ₂ ·（H ₂ O）₃ } _n（5）和{[锌₂（bpee）₂（FUM）₂ ]·（H ₂ O）} _Ñ（6），具有像一个相似的结构关系3和4分别5，并用柱撑层结构6用5折互穿菱形网络。所有化合物均已通过粉末X射线衍射（PXRD），元素分析，红外（IR）光谱，UV可见光谱和热重分析进行了全面表征。已对具有3D结构的化合物3 – 6进行了气体/溶剂蒸气吸附研究。在3的情况下，观察到有趣的可逆的晶体到晶体的转变，已通过PXRD分析，IR光谱和UV-vis光谱进行了深入研究。在室温下对所有配合物进行固态发射光谱分析。