Synthesis, Structures, And Properties Of Coordination Polymers Based On Bent Ligands And Mixligands

The design and construction of coordination polymers have attracted extensive interest in recent years, due to their various structural topologies and potential applications in gas absorption and separation, catalysis, and the development of electronic, optical, magnetic and sensing materials. It is well known that the properties of coordination polymers are heavily influenced by their structures. Therefore, it is important for crystal engineering to investigate the factors influencing the structural construction of functional compounds. Although large numbers of coordination polymers with interesting structures and excellent properties have been widely reported in recent years, it still remains a challenging task to explore effective synthetic strategies for the preparation of coordination polymers with expected structure and properties due to the fact that too many factors will influence the terminal structures of coordination polymers. In the paper, we choose ligands with different configurations to construct 38 metal-organic coordination polymers. The corresponding structural topologies and properties have been studied. These researches mainly include the following aspects:(1) Twelve Cu(I) coordination polymers, [CuCl(4-bpt)]n (1), [Cu4I4(4-bpt)2]n (2), {[Cu2I2(4-bpt)]·0.5I2}n (3), [Cu3I3(4-bpt)]n (4), [Cu2Br2(4-bpt)]n (5), [CuBr(4-bpt)]n (6), [Cu2Cl2(4-bpt)]n (7), [Cu2Br2(3-bpt)]n (8), [CuBr(3-bpt)]n (9), [CuI(3-bpt)]n (10), [Cu3I3(3-bpt)]n (11), and Cu2I2(2-bpt)2 (12) (4-bpt = 4-amino-3,5-bis(4-pyridyl)- 1,2,4-triazole, 3-bpt = 4-amino-3,5-bis(3-pyridyl)-1,2,4- triazole and 2-bpt = 4-amino- 3,5-bis(2-pyridyl)-1,2,4-triazole), have been prepared and structurally characterized. In these compounds, n-bpt (4-amino-3,5-bis(n-pyridyl)- 1,2,4-triazole) exhibits different coordination modes tuned by the isomeric effect and the anion effect, forming various architectures by bridging a variety of CuX (X= Cl, Br or I) building units. Compound 1 presents a layer structure with (4, 4) topology built by bridging adjacent (CuCl)∞chains with 4-bpt. Compound 2 shows an unusual 1D strap structure by linking rare Cu8I8 unit with 4-bpt. Compounds 3 and 4 present 2D layers with (6, 3) topology. Compound 5 shows a 3D ZnCl2 network with {3.6.74}{3.62.73}2 topology. Compound 6 exhibits a layer with (4, 82) network topology. A complicated 3D framework for 7 is constructed with unique {6.82}2{6.85} topology. Compounds 8 and 9 are both chains, and hydrogen-bonding andπ-πinteractions play important roles in stabilizing the extended structure. Compound 10 is a layer with (4, 4) topology. An interesting double layer compound exhibiting complicated structure is found for 11. Compound 12 is a zero-periodic compound. The luminescent properties of compounds 4-6, 8, 9, and 12 have been investigated in the solid state.(2) Eight coordination polymers, [Mn4.5(BCPAT)4(OH)(H2O)10.5]n (13), [Cu(BCPAT)(H2O)1.375]n (14), {Zn(BCPAT)(DMF)[(CH3)2NH]0.25}n (15), [Zn(BCPAT) (4,4'-bipy)0.5(DMF)0.25(H2O)0.25]n (16), [Zn2(BCPAT)2(bib)(H2O)6.75]n (17), [Cd2 (BCPAT)2(H2O)7.5]n (18), [Cd(BCPAT)(bpp)]n (19), [Cd(BCPAT)(bib)0.5(H2O)3]n (20), (BCPAT = 4-amino-3,5-bis(3-carboxyphenyl)-1,2,4-triazole, bib = 1,4-bis(imidazol) butane, bpp = 1,3-bi(4-pyridyl)propane), have been prepared and structurally characterized with adjusting the roles of different organic bases such as Et3N, DABCO, 4,4-bipy, bib, and bpp. In these compounds, BCPAT exhibits different coordination modes and conformations constructing various architectures by bridging a variety of building units and by adjusting the roles of different organic bases. Compound 13 presents a 3D diamond topology built by bridging rare Mn9 clusters with BCPAT. Compound 14 shows a unique 2D {42.6}2{44.69.82} topology by linking paddle-wheel SBU with BCPAT. Compound 15 is a 1D double chain structure. Compound 16 presents an unusual 2D V2O5 net with {42.63.8}{42.6} topology by linking 4,4'-bipy with the double chains constructed by BCPAT and Zn(II) atoms. Compound 17 exhibits a rare 3D coe topology with point (Schlafli) symbol for net: {42.6.102.12}{42.6}. Compound 18 presents an unusual 1D strap shaped structure. Compound 19 shows an interesting 4-connected 2D interpenetrating net with point (Schlafli) symbol {44.62}. Compound 20 is a 1D"H"shaped structure when it is viewed from c axis direction. The luminescent properties of compounds 15-18, 20, and the magnetic properties of compound 13 have been investigated in the solid state.(3) Two interesting coordination polymers [Cu(C2O4)(dpt)0.5(H2O)2.5]n (21) (dpt=3,5-bipyridyl-1,2,4-triazole) with rare NiP2 topology and kgd topology have been prepared through in situ ligand deaminization reaction and [Cu3O2(NO3)2(bpni)2(H2O)2]n (22) {bpni =5-(3-pyridyl)-1,2,4-triazolo[3,2- c](7-aza-1- H-indazole)} and in situ ligand intramolecular amination cyclization reaction, respectivly. To the best of our knowleclization reaction is reported for the first time. Meantime, the magnetic properties of the coordination polymers have been studied.(4) Five coordination polymers, [Mn2(NBPDC)2(bpp)]n (23), [Co4(NBPDC)4 (bpp)2(H2O)5.25]n (24), [Ni(NBPDC)(bpp)(H2O)2]n (25), [Zn(NBPDC) (bpp)]n (26) and [Cd2(NBPDC)2(bpp)]n (27) (NBPDC=2,2'-dinitro-4,4'- biphenyldicarboxyl acid, bpp=1,3-bi(4-pyridyl)propane), have been prepared and structurally characterized. In these compounds, NBPDC and bpp exhibit different coordination modes tuned by different metal ions, constructing various architectures by bridging a variety of inorganic building units. Compound 23 presents a hex net with point symbol for net: {36.418.53.6}. Compound 24 shows a self-penetrating ilc topology by linking Co4 clusters with NBPDC and bpp. Compound 25 presents a 2D structure with (4, 4) topology. Compound 26 shows a diamond network with 5-fold interpenetrating architecture, featuring left-handed and right-handed helix chaiesents a pcu topology by linking rod-shaped secondary building units. The magnetic properties of compounds 23 and 24 have been characterized.(5) Six coordination polymers, Mn2(NBPDC)2(bib) (28), Co2(NBPDC)2(bib)1.5 (H2O)2 (29), Ni2(NBPDC)2(bib)1.5(H2O)2 (30), Cu3(NBPDC)2(bib)(OH)2 (31), Zn2(NBPDC)2(bib) (32), and Cd2(NBPDC)2(bib)(H2O) (33), (NBPDC = 2,2'- dinitro-4,4'-biphenyldicarboxyl acid, bib = 1,4-bis(imidazol)butane), have been prepared and structurally characterized. In these compounds, NBPDC and bib link different secondary building units (SBUs) to construct various architectures based with charming molecular topologies and functional properties as well as afford eywords: metal-organic coordination polymer, crystal structure, topology analysis, magnetism, luminescence on different metals. Compounds 28 and 32 present 3D pcu net based on infinite rod-shaped SBU. Compounds 29 and 30 have the same 2D double-layer structure with unique {412.52.6} topology, showing an interesting self-penetration feature. Compound 31 presents a 3D framework with hex topology. Compound 33 shows a 3D framework with unprecedented (412.513.63)(48.55.62) topology based on two different unusual infinite and finite SBUs, and has an interesting self-penetrating ature. Therefore, different metal ions influence the final structures of coordination polymers. The magnetic properties of compounds 28 and 31 have been characterized.(6) Five coordination polymers, Mn2(NBPDC)2(bip)0.5(H2O) (34), Co2.5(NBPDC)2 (bip)(H2O)3(OH) (35), Cu2.5(NBPDC)2(bip)(H2O)(OH) (36), Zn2.5(NBPDC)2(bip) (OH) (37), Cd2(NBPDC)2(bip) (38), (nbpdc = 2,2'-dinitro-4,4'-biphenyldicarboxyl acid, bip = 1,5-bis(imidazol)pentane), have been prepared and structurally characterized. Compound 34 presents 3D hex net based on infinite rod-shaped SBU. Compound 35 is a 3D mab topology showing an interesting self-penetration feature by NBPDC and bip linking Co5 clusters. Compound 36 is a 3D pcu topology bas Cu5 clusters. Compounds 37 and 38 are both 3D pcu topologies based on infinite SBUs. The magnetic properties of compounds 34 and 35 have been characterized.In summary, we have investigated the influences of organic ligands, metal ions, anions, and organic bases on the building blocks and structures of coordination polymers which were synthesized by different methods such as slow evaporation, reactant diffusion, and hydrothermal reaction. We have prepared a series of MOFs with charming topologies, and studied their potential application as optical, and magnetic materials. We believe that these results could facilitate the exploration of new MOFsacademic bases for directing the synthesis of novel architectures.