| In this presentation, we report the syntheses, crystal structures and properties of the metal coordination complexes constructed from 4-sulfobenzoate (4-sb). In the procedures of syntheses, we chose 2,2'-bipyridine (2,2'-bipy), 4,4'-bipyridine (4,4'-bipy), 1,10-phenanthroline (1,10-phen) and 8—hydroxyquinoline (HQ) as neutral ligands, and lead, copper, zinc, cadmium and manganese as metal ions in our research. Totally, we got eighteen compounds, listed as follows:1. For lead complexes, we focused on the effect of neutral ligands on the structures. We discuss six lead(Ⅱ) complexes and one organic complex: {[b(4-sb)(phen)]·(H2O)}n (1), [Pb(4-sb)(2,2'-bipy)]n (2), [Pb2(4-sb)2(H2O)2]n(3), [Pb2(4-sb)2(H2O)4]n (4), {[Pb(4-sb)(4,4'-bipy)1/2]'(4,4'-bipy)1/2}n(5), [Pb(4-sb)2(H2O)2]2-[(H2Q)2]2+·4H2O (6) and [Hbpe]22+ [4.sb]<sup>2-·3H2O(7). Complexes 1 and 2 consist of 2-D networks in which the Pb(Ⅱ) atoms are seven-coordinated to terminal ligands and sb2-. In complexes 3 and 4, the lead(Ⅱ) atoms are surrounded by 4-sb ligands and water molecules. The molecular structure of the complex 3 is a 3-D network, while 4 is a 1-D linear chain. Complex 5 is a 3-D coordination polymer with 1-D cavities, filled with 4,4'-bipy guest molecules. In the 1-D complex 6, the neutral ligand is protonated and non-coordinating. The coordination numbers of Pb(Ⅱ) atoms are seven in complexes 1, 2 and 6, and six in complex 4, six and seven in complex 3, where the lone electron pairs are all stereo-chemical activity. However, in complex 5 the lone electron pair is stereo-chemical inactivity. In a word, we can analyse the coordination environment of Pb(Ⅱ) atoms according to the following regulations: (1) the effect of neutral ligands; (2) the impact of lone pair electron; (3) the short contacts near lead(Ⅱ) atoms; (4) the bond Value of lead.2. For transition metal (Cu, Zn, Cd, Mn) complexes constructed from 4,4'-bipy and 4-sb, we report the diverse coordination modes of 4,4'-bipy ligands. We have synthesized seven compounds: {[Cu(4,4'-bipy)(H2O)4](4-sb)}n(8), [Zn(4,4'-bipy)2(H2O)4] (4-Hsb)2(9), {[Zn(4,4'-bipy) (H2O)4] (4-sb)}n(10), [Mn(4,4'-bipy)2(H2O)4] (4-Hsb)2(11), [Mn(4,4'-bipy)2(H2O)4](4-sb)(4H2O) (12), {[Mn(4-sb)(4,4'-bipy)(H2O)3] (2H2O)}n(13), {[Cd2(4-sb)2(4,4'-bipy)4(H2O)3]4H2O}n(14).In complexes 8 and 10, the 4,4'-bipy ligands are bidentate, generating1-D chains; while the most interesting topological feature in complexes 9 and 11-13, is the monodentate function for 4,4'-bipy. It is worth noting that the 4,4'-bipy ligands exhibit three kinds of coordination modes in complex 14, which is sparse. Successful exploration in these seven complexes may provide useful information for other combination systems with 4,4'-bipy to control the coordination ability of bridging ligands and construct novel functional frameworks with specific topologies.3. We research ulterriorly the effect of terminal ligands (2,2'-bipy, 1,10-phen) on the coordination geometries of Mn-4-sb system. Three complexes are synthesized in this chapter: [Mn(phen)2(H2O)2](4-sb)·6.5H2O(15), [Mn(4-Hsb)2(phen)2] (16) and [Mn(4-sb)(2,2'-bipy)(H2O)3]·H2O(17). Complexes 15 and 16 were obtained from the same reactant system, but they have different composition and structures. In complex 15, the 4-sb ligand does not coordinate to Mn2+ ion and only acts as counteranion, while in complex 16, the 4-sb ligand coordinates to metal ion. There are two main factors govern the diverse structures of complexes 15 and 16: (1) reaction time and temperature, that is to say, complex 15 is kinetically stable complex, while complex 16 is thermally stable one. (2) pH value, complex 15 was grown from aqueous solution with higher pH (≈6), while for 16, the pH value is lower (≈4).4. Hydro(solvo)thermal in situ ligand synthesis has been rapidly developed over the past several years due to its effectiveness, simplicity and environmental friendliness. However, up to now, most of the mechanisms of the in situ ligand syntheses have not been very clear. When we put copper nitrate, 4-sb and 4,4'-bipy together under hydrothermal conditions, complex Cu3(SO4)(OH)4(18) was obtained. Furthermore, no sulfonate was used in the preparation of 18, which was the product of the hydrolysis of 4-sb. The work about in situ ligand synthesis of 4-sb has been done a little, and we will make greater efforts on it in the future. |
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