Endo- and Exocyclic Supramolecular Complexes of Mixed-Donor Macrocycles via [1:1] and [2:2] Cyclizations

A 20-membered N₂O₂S₂ macrocycle (<b>L</b>^<b>1</b>) and a 40-membered N₄O₄S₄ macrocycle (<b>L</b>^<b>2</b>) obtained from the mixed products via respective [1:1] and [2:2] cyclization are employed, and a comparative investigation of the coordination behavior of these macrocyclic ligands with nickel­(II), cadmium­(II), and silver­(I) is reported. The X-ray structures of seven complexes (<b>1</b>–<b>7</b>) have been determined, and a range of structural types and coordination modes, including mono- to multinuclear and endo- to exocyclic coordination, is presented. The cation-dependent endocyclic 1:1 (metal-to-ligand) complex [Ag­(<b>L</b>^<b>1</b>)]­NO₃ (<b>1</b>) and a sandwich-like 1:2 [Cd­(<b>L</b>^<b>1</b>)₂]­(NO₃)₂ (<b>2</b>) complex exhibiting different stoichiometries and metal positions in the complexes were obtained by the reactions of the smaller macrocycle <b>L</b>^<b>1</b> with AgNO₃ and Cd­(NO₃)₂, respectively. Meanwhile, the reactions of <b>L</b>^<b>1</b> with Ni­(ClO₄)₂·6H₂O and Ni­(NO₃)₂·6H₂O afforded the anion-dependent perching-type mononuclear solvato-complex [Ni­(<b>L</b>^<b>1</b>)­(CH₃CN)₃]­(ClO₄)₂­·2CH₃CN (<b>3</b>) and the sandwich-like complex [Ni­(<b>L</b>^<b>1</b>)₂(NO₃)₂] (<b>4</b>), respectively. In the complexations of the larger macrocycle <b>L</b>^<b>2</b> with AgNO₃, two endocyclic dinuclear complexes [Ag₂(<b>L</b>^<b>2</b>)­(CH₃CN)₂]­(NO₃)₂ (<b>5</b>) and [Ag₂(<b>L</b>^<b>2</b>)]­(NO₃)₂ (<b>6</b>) with different coordination environments were isolated as a kinetic (<b>5</b>) and thermodynamic controlled (<b>6</b>) products in neutral condition. The identical reaction in acidic condition afforded a stairtype one-dimensional (1-D) coordination polymer {[Ag₂(H₄<b>L</b>^<b>2</b>)­(μ₂-NO₃)­(NO₃)₂]­(NO₃)₃­·CH₃CN­·3H₂O}_<i>n</i> (<b>7</b>) in which the disilver­(I) complex cation units are connected by nitrate ions. From these results, the effects of the cation, anion, and size ratio on the topologies of the resulting solid complexes are discussed. NMR titrations of <b>L</b>^<b>1</b> and <b>L</b>^<b>2</b> with silver­(I) nitrate were also carried out to explore their complexation behaviors in solution and for comparison with the solid state structures

Endo- and Exocyclic Supramolecular Complexes of Mixed-Donor Macrocycles via [1:1] and [2:2] Cyclizations

A 20-membered N₂O₂S₂ macrocycle (<b>L</b>^<b>1</b>) and a 40-membered N₄O₄S₄ macrocycle (<b>L</b>^<b>2</b>) obtained from the mixed products via respective [1:1] and [2:2] cyclization are employed, and a comparative investigation of the coordination behavior of these macrocyclic ligands with nickel­(II), cadmium­(II), and silver­(I) is reported. The X-ray structures of seven complexes (<b>1</b>–<b>7</b>) have been determined, and a range of structural types and coordination modes, including mono- to multinuclear and endo- to exocyclic coordination, is presented. The cation-dependent endocyclic 1:1 (metal-to-ligand) complex [Ag­(<b>L</b>^<b>1</b>)]­NO₃ (<b>1</b>) and a sandwich-like 1:2 [Cd­(<b>L</b>^<b>1</b>)₂]­(NO₃)₂ (<b>2</b>) complex exhibiting different stoichiometries and metal positions in the complexes were obtained by the reactions of the smaller macrocycle <b>L</b>^<b>1</b> with AgNO₃ and Cd­(NO₃)₂, respectively. Meanwhile, the reactions of <b>L</b>^<b>1</b> with Ni­(ClO₄)₂·6H₂O and Ni­(NO₃)₂·6H₂O afforded the anion-dependent perching-type mononuclear solvato-complex [Ni­(<b>L</b>^<b>1</b>)­(CH₃CN)₃]­(ClO₄)₂­·2CH₃CN (<b>3</b>) and the sandwich-like complex [Ni­(<b>L</b>^<b>1</b>)₂(NO₃)₂] (<b>4</b>), respectively. In the complexations of the larger macrocycle <b>L</b>^<b>2</b> with AgNO₃, two endocyclic dinuclear complexes [Ag₂(<b>L</b>^<b>2</b>)­(CH₃CN)₂]­(NO₃)₂ (<b>5</b>) and [Ag₂(<b>L</b>^<b>2</b>)]­(NO₃)₂ (<b>6</b>) with different coordination environments were isolated as a kinetic (<b>5</b>) and thermodynamic controlled (<b>6</b>) products in neutral condition. The identical reaction in acidic condition afforded a stairtype one-dimensional (1-D) coordination polymer {[Ag₂(H₄<b>L</b>^<b>2</b>)­(μ₂-NO₃)­(NO₃)₂]­(NO₃)₃­·CH₃CN­·3H₂O}_<i>n</i> (<b>7</b>) in which the disilver­(I) complex cation units are connected by nitrate ions. From these results, the effects of the cation, anion, and size ratio on the topologies of the resulting solid complexes are discussed. NMR titrations of <b>L</b>^<b>1</b> and <b>L</b>^<b>2</b> with silver­(I) nitrate were also carried out to explore their complexation behaviors in solution and for comparison with the solid state structures

Schematic diagram of the metabolic pathway and relative levels of the major compounds detected in <i>C. pruinosa</i> extracted with 70% MeOH and 100% <i>n-</i>hexane plus D₂O.

<p>This was modified from pathways presented in KEGG database (<a href="http://www.genome.jp/kegg/" target="_blank">http://www.genome.jp/kegg/</a>). ANOVA was performed to assess the statistical significance of differences between samples (p<0.05). Data are mean values with error bars representing standard deviation values. Different letters in bars represent the difference of statistical significance of metabolites levels. The superscript numbers in compounds represent analysis methods. 1: NMR analysis of D₂O extracts, 2: GC-MS analysis of 70% methanol extracts, 3: GC-MS analysis of n-hexane extracts.</p

Assignment of ¹H NMR spectral peaks for <i>C. pruinosa</i> mycelia using D₂O extracts.

<p>Assignment of ¹H NMR spectral peaks for <i>C. pruinosa</i> mycelia using D₂O extracts.</p

Chromatographic data of the identified compounds from the 100% <i>n</i>-hexane extract of <i>C. pruinosa</i> mycelia analyzed using GC-MS.

<p>Chromatographic data of the identified compounds from the 100% <i>n</i>-hexane extract of <i>C. pruinosa</i> mycelia analyzed using GC-MS.</p

Morphological characteristics of <i>C. pruinosa</i> mycelia cultivated under various conditions.

<p>Left photo in each condition: front of plate. Right photo in each condition: back of plate. (A) S+L condition; (B) S+D condition; (C) L+D condition; (D) SL+D condition; (E) SF+D condition, (F) N+D condition.</p

The list of metabolites identified by ¹H NMR and GC-MS analysis.

<p>The list of metabolites identified by ¹H NMR and GC-MS analysis.</p

Composition of growth medium and light conditions for cultivation of <i>C. pruinosa</i> mycelia.

<p>*KH₂PO₄ 10 g/L, MgSO₄ 7H₂O 5 g/L, CaCl₂ 2H₂O 1 g/L. **CuSO₄ 5H₂O 0.04 mg/100 mL, BO₃H₃ 0.5 mg/100 mL, ZnSO₄ 7H₂O 0.4 mg/100 mL, MnSO₄ H₂O 0.4 mg/100 mL, NaMoO₄ 2H₂O 0.2 mg/100 mL. ***0.005% amino acid (L-glutamic acid, L-methionine, L-lysine, L-leucine, L-isoleucine).</p

PCA score plots of <i>C. pruinosa</i> mycelia cultivated under various conditions.

<p>(A) D₂O extracts characterized using NMR analysis. (B) 70% methanol extracts and (C) 100% <i>n</i>-hexane extracts characterized using GC-MS analysis. PCA, Principal component analysis.</p

Antioxidant ability and total phenolic content of the 70% methanol extracts of <i>C. pruinosa</i> mycelium grown in different cultivation conditions.

<p>GAE: gallic acid equivalents.</p