Metal–Organic Frameworks Constructed from Group 1 Metals (Li, Na) and Silicon-Centered Linkers

A series of “light metal” metal–organic frameworks containing secondary building units (SBUs) based on Li⁺ and Na⁺ cations have been prepared using the silicon-centered linkers Me_<i>x</i>Si­(<i>p</i>-C₆H₄CO₂H)_4‑<i>x</i> (<i>x</i> = 2, 1, 0). The unipositive charge, small size, and oxophilic nature of the metal cations give rise to some unusual and unique SBUs, including a three-dimensional nodal structure built from sodium and oxygen ions when using the triacid linker (<i>x</i> = 1). The same linker with Li⁺ cations generated a chiral, helical SBU, formed from achiral starting materials. One-dimensional rod SBUs are observed for the diacid (<i>x</i> = 2) and tetra-acid (<i>x</i> = 0) linkers with both Li⁺ and Na⁺ cations, where the larger size of Na⁺ compared to Li⁺ leads to subtle differences in the constitution of the metal nodes

Anti-nicotine antibody titer and function in mice.

<p>Panel A: BALB/c mice (n = 12/gp) were immunized by IM injection with 10 µg of different nicotine Hapten-DT conjugates adjuvanted with Al(OH)₃ (40 µg Al³⁺) + CpG 24555 (50 µg) on days 0, 28 and 42. Plasma was collected on day 54 and anti-nicotine antibody levels determined by ELISA (Panel A). On day 56 animals received an IV injection of ³H-nicotine (0.05 mg/kg) and plasma and brains collected. Panel B shows nicotine levels in plasma (ng-eq/mL), and Panel C shows nicotine levels in brain (ng-eq/g).</p

General scheme for addition of different linkers to Hapten 7.

<p>General scheme for addition of different linkers to Hapten 7.</p

Structures of different linker-modified nicotine hapten.

<p>Structures of different linker-modified nicotine hapten.</p

Synthesis of Hapten 8.

<p>Synthesis of Hapten 8.</p

Synthesis of Hapten 10.

<p>Synthesis of Hapten 10.</p

Synthesis of Hapten 5.

<p>Synthesis of Hapten 5.</p

Synthesis of Hapten 9.

<p>Synthesis of Hapten 9.</p

Nicotine and hapten structures.

<p>The thioacetate of Hapten 8 was deprotected to the thiol for coupling with DT.</p

Anti-nicotine antibody titer and function in mice.

<p>Panel A: BALB/c mice (n = 12/gp) were immunized by IM injection with 10 µg of different nicotine Hapten-DT conjugates adjuvanted with Al(OH)₃ (40 µg Al³⁺) + CpG 24555 (50 µg) on days 0, 28 and 42. Plasma was collected on day 54 and anti-nicotine antibody levels determined by ELISA (Panel A). On day 56 animals received an IV injection of ³H-nicotine (0.05 mg/kg) and plasma and brains collected. Panel B shows nicotine levels in plasma (ng-eq/mL), and Panel C shows nicotine levels in brain (ng-eq/g).</p