Synthesesp,Structures And Properties Of Coordination PolymersConstructed Based On Multidentate Organic Acid Ligands

As well-known, coordination polymers have attracted much more attention not only because of their versatile structures and topologies but also for their potential applications as functional materials. Coordination polymer (CPs), a class of hybrid crystalline materials formed by the self-assembly of polydentate bridging ligands and metal-connecting points with one-, two- and three-dimensional periodic fashion, have drawn great attention because of a wide variety of structures and their extraordinarily functional properties in material science. It is demonstrated that CPs have been synthesized from the assembly of organic ligands with metal ions or metal clusters based on deliberate selection and rational designs as a result of interesting structural topologies. At present, they can exhibit extremely high surface areas, wide variety of structures, fine control over pore size, as well as tunable pore shape and functionality. Structural analyses show that metal ions and the inherent advantages of organic linkers(coordination environments:dentate number or mode, coordinate distance) are the most important factor that influences coordination polymer assembly. Metal ions determine the type of metal centre and structural topology. Meanwhile, the forming of CPs may also be affected by synthetic route, and some other external stimuli such as solvent, pH condition, temperature change, etc. during crystal growth.The study on synthetic conditions and rules for these new compounds, topological analyses, and the exploration of relationships between structures and properties for these new compounds are also carried out.In this paper, we select multi-carboxylic acid as organic ligands in view of its following characteristics:(i) would be partially or completely deprotonated by tuning the reaction pH value; (ii) It can act as not only hydrogen-bond acceptor but also hydrogen-bond donor, depending upon the degree of deprotonation, which are good for stabilizing and extending the solid-state structures.Therefore, we utilize three multidentate organic acid(H2L; 4, 4’-(phenylazanediyl)dibenzoic acid, H3L’:3,5-bi(4-carboxy-phenoxy) benzoic acid, H6L"; 2,2",2’",5,4",4’"-hexcarboxylic acid) and N-donor ligands with versatile conformations, and according to the principle of molecular recognition and assembly, we have constructed 34 coordination compounds have been synthesized on the basis of hydrothermal and solvothermal synthesis methods, and structurally characterized by elemental analyses, IR, PXRD, TG and single crystal X-ray diffractions. The thermal stabilities and fluorescent activity of these compounds have been studied. The main results are as follows:(1) Based on 4,4’-(phenylazanediyl)dibenzoic acid, under suitable conditions, we have synthesized 24 coordination polymers of novel structures, namely [ZnL(bpmp)0.5]·3H2O (1), [Zn2L2(bibp)2]·H2O (2), [ZnL(bpp)]·7H2O (3), [Zn2L2(bidpe)2]·2H2O (4), [Zn3L3(bpmp)0.5·(H2O)2] (5), [ZnL(bibpip)2]·3H2O (6), [ZnL(bpmb)] (7), [ZnL(bib)]·DMF·4H2O (8), [ZnL(bibp)]·2DMF (9), [ZnL(bimb)] DMF (10), [ZnL(bimb)]·6(H2O)0.5 (11), [ZnL(bimp)0.5]·3H2O (12), [ZnL(bimp)]·7H2O (13), [CdL(bpmp)·H2O]·H2O·DMF (14), [Cd2L2(bpmp)2]·3H2O·2DMF (15), [CdL(bimb)0.5]·2H2O (16), [CdL(bpmb)0.5]n (17), [Cu2L(bpmp)] (18), [CuL(bpmb)0.5]·DMF (19), [Mn2L2(phen)2]·DMF (20), Mn2L2(bibp)2 (21), [Ni2L2(bib)2·2H2O]·5H2O (22), [Ni(HL)2(bpy)] (23), [Ni2L2(bibpip)2·2H2O]·6H2O (24).Their structures have been depicted and compared in details.Compound 1 exhibits an infinite 3D structure with{44·610·8} topology. Compound 2 features an unusual two-fold interpenetrating 3D framework with{319·417·59} topology. Compound 3 shows the interweaving helical chains. Compound 4 views of 2-fold 1D chains are mutually interpenetrate each other from 2D sheets. Compound 5 exhibits an unusual 2D wave-like sheet. Compound 6 shows the 5-fold interpenetrating framework. Compound 7 displays a 1D chain. Compound 8 is also (4,4) layer structure which can be split into interesting helixes. Compound 9 shows the three-fold interpenetrating sheets are stacked in ABAB fashion and form a 3D framework. Compound 10 exhibits an infinite 4-fold interpenetrated 3D framework with (66) topology. Compound 11 displays the 2D undulated sheets leading to form a 3D framework with π-π interactions among layers in ABAB fashion. Compound 12 shows an infinite 2-fold interpenetrated 3D framework with (412·63) topology. Compound 13 exhibites 2D layer with{42·63·8} topology structure. compound 14 shows 4-fold interpenetrating 3D framework with{65·8} topology structure. Compound 15 gave a 2D framework view of the helical chains with{36·46·53} topology structure. compound 16 exhibites 2D framework. Compound 17 gave a 1D zigzag chains are mutually interpenetrate each other by H-bond from framework structure. compound 18 shows 2D layer. Compound 19 gave a 3D framework with{44·610·8} topology structure. Compound 20 is composed of a one-dimensional beaded chain conjugation through π-π assembled into a 3D framework. Compound 21 exhibits 2D sheet. The sheets are stacked in ABAB fashion and form a 3D framework. compound 22 exhibited 2D layer with {42·65·8} topology structure. Compound 23 gave a 3D framework with{48·54·63} topology structure. compound 24 exhibits a 5-fold interpenetrating 3D framework with a {44·62} topology.(2) Based on 3,5-bi(4-carboxy-phenoxy) benzoic acid and N-donor ligands with versatile conformations, and according to the principle of molecular recognition and assembly, we have constructed four ternary coordination polymers, namely[Cd3(L’)2(BIP)2]·2H2O·DMF (25), [Cd3(L’)2(bip)2·2H2O] (26), [Cu1.5(L’)(bpmp)0.5(H2O)0.5]·DMF (27), [Zn3(L’)2(bip)·2H2O] (28). Their structures were depicted in details, and the differences between them that result from the conformation of N-donor ligands discussed. Compound 25 display 2D sheet. Compound 26 is trinuclear Cd(II) secondardedy building units (SBUS) can be regarded as 6-connected nodes to form a 2D layered network. compound 27 exhibits 3D framework with (4·82)(86)(42·68·83·9·10) topology. Analyzing carefully, we found in the 3D framework displays a self-penetrating phenomenon. Compound 28 shows similar baskets the trinuclear Zn(Ⅱ) SBUs 3D framework with (42·6)2(44·62·88·10) topology structure.Meanwhile, the fluorescent and TGA properties of some compounds have been characterized.(3) Based on 2,2",2’",5,4",4’"-hexcarboxylic acid synthesized six multi-topic ligands with the mixture of N-donors and carboxylates. Under suitable conditions, six coordination polymers, namely [Cu1.5(H2L")0.5(H4L)0.5(bibp)1.5]·3H2O (29), [Zn1.5L"0.5(bib)(H2O)]·8H2O (30), [Zn1.5L"0.5(bibp)1.5]·DMF (31), [Co0.5(H4L")0.5(bibpip)(H2O)]-3H2O (32), [Zn(H2L")0.5(tip)] (33), [Cu(H4L)0.5(H6L")0.5(tip)(H2O)]·2H2O (34) have been isolated.Compound 29 exhibits an infinite 3D structure with (53·6·72)(52·62·7·8)2 topology. Compound 30 features an unusual exhibiting (3,4,6)-connected 3D framework with (54·66·72·8·92) (52·6) (52·64) topology. Compound 31 shows (4,6)-connected 3D framework with (56·62·74·83) (55·7) (52·6·7·82) topology. Compound 32 views of 2D sheets. Compound 33 exhibits an unusual two-fold interpenetrating 3D framework with (66) (64·82) topology. Compound 34 shows (3,4)-connected binodal 2D net with the (42·6)(42·63·8) topology. Their structures and properties have also been studied in details.