3 research outputs found
Through-Space Paramagnetic NMR Effects in Host–Guest Complexes: Potential Ruthenium(III) Metallodrugs with Macrocyclic Carriers
No full textThe
potential of paramagnetic ruthenium(III) compounds for use as anticancer
metallodrugs has been investigated extensively during the past several
decades. However, the means by which these ruthenium compounds are
transported and distributed in living bodies remain relatively unexplored.
In this work, we prepared several novel ruthenium(III) compounds with
the general structure Na<sup>+</sup>[<i>trans</i>-Ru<sup>III</sup>Cl<sub>4</sub>(DMSO)(L)]<sup>−</sup> (DMSO = dimethyl
sulfoxide), where L stands for pyridine or imidazole linked with adamantane,
a hydrophobic chemophore. The supramolecular interactions of these
compounds with macrocyclic carriers of the cyclodextrin (CD) and cucurbit[<i>n</i>]uril (CB) families were investigated by NMR spectroscopy,
X-ray diffraction analysis, isothermal titration calorimetry, and
relativistic DFT methods. The long-range hyperfine NMR effects of
the paramagnetic guest on the host macrocycle are related to the distance
between them and their relative orientation in the host–guest
complex. The CD and CB macrocyclic carriers being studied in this
account can be attached to a vector that attracts the drug-carrier
system to a specific biological target and our investigation thus
introduces a new possibility in the field of targeted delivery of
anticancer metallodrugs based on ruthenium(III) compounds
Through-Space Paramagnetic NMR Effects in Host–Guest Complexes: Potential Ruthenium(III) Metallodrugs with Macrocyclic Carriers
No full textThe
potential of paramagnetic ruthenium(III) compounds for use as anticancer
metallodrugs has been investigated extensively during the past several
decades. However, the means by which these ruthenium compounds are
transported and distributed in living bodies remain relatively unexplored.
In this work, we prepared several novel ruthenium(III) compounds with
the general structure Na<sup>+</sup>[<i>trans</i>-Ru<sup>III</sup>Cl<sub>4</sub>(DMSO)(L)]<sup>−</sup> (DMSO = dimethyl
sulfoxide), where L stands for pyridine or imidazole linked with adamantane,
a hydrophobic chemophore. The supramolecular interactions of these
compounds with macrocyclic carriers of the cyclodextrin (CD) and cucurbit[<i>n</i>]uril (CB) families were investigated by NMR spectroscopy,
X-ray diffraction analysis, isothermal titration calorimetry, and
relativistic DFT methods. The long-range hyperfine NMR effects of
the paramagnetic guest on the host macrocycle are related to the distance
between them and their relative orientation in the host–guest
complex. The CD and CB macrocyclic carriers being studied in this
account can be attached to a vector that attracts the drug-carrier
system to a specific biological target and our investigation thus
introduces a new possibility in the field of targeted delivery of
anticancer metallodrugs based on ruthenium(III) compounds
Construction of Larger Molecular Aluminophosphate Cages from the Cyclic Four-Ring Building Unit
No full textNew molecular aluminophosphates of
different nuclearity are synthesized
by a stepwise process and structurally characterized. The alkane elimination
reaction of bis(trimethylsiloxy)phosphoric acid, OP(OH)(OSiMe<sub>3</sub>)<sub>2</sub>, with trialkylalanes, AlR<sub>3</sub> (R = Me,
Et, <sup>i</sup>Bu), provides the cyclic dimeric aluminophosphates,
[(AlR<sub>2</sub>{μ<sub>2</sub>-O<sub>2</sub>P(OSiMe<sub>3</sub>)<sub>2</sub>})<sub>2</sub>] (R = Me (<b>1</b>), Et (<b>2</b>), <sup>i</sup>Bu (<b>3</b>)). Unsymmetrically substituted
cyclic aluminophosphonate [(AlMe<sub>2</sub>{μ<sub>2</sub>-O<sub>2</sub>P(OSiMe<sub>3</sub>)(<sup>c</sup>Hex)})<sub>2</sub>] (<i>cis/trans</i>-<b>4</b>) is prepared by dealkylsilylation
reaction of <sup>c</sup>HexP(O)(OSiMe<sub>3</sub>)<sub>2</sub> with
AlMe<sub>3</sub>. Molecules <b>1</b>–<b>4</b> containing
the [Al<sub>2</sub>(μ<sub>2</sub>-O<sub>2</sub>P)<sub>2</sub>] inorganic core are structural and spectroscopic models for the
single four-ring (S4R) secondary building units (SBU) of zeolite frameworks.
Compound <b>1</b> serves as a starting point in construction
of larger molecular units by reactions with OP(OH)(OSiMe<sub>3</sub>)<sub>2</sub> as a cage-extending reagent and with diketones, such
as Hhfacac (1,1,1,5,5,5-hexafluoropentan-2,4-dione) and Hacac (pentan-2,4-dione),
as capping reagents. Reaction of <b>1</b> with 4 equiv of Hhfacac
leads to new cyclic aluminophosphate [(Al(hfacac)<sub>2</sub>{μ<sub>2</sub>-O<sub>2</sub>P(OSiMe<sub>3</sub>)<sub>2</sub>})<sub>2</sub>] (<b>5</b>), existing in two isomeric (<i>D</i><sub>2</sub> and <i>C</i><sub>2<i>h</i></sub>) forms.
Reaction of <b>1</b> with 2 equiv of OP(OH)(OSiMe<sub>3</sub>)<sub>2</sub> and 1 equiv of Hhfacac provides a molecular aluminophosphate
[AlMe{Al(hfacac)}<sub>2</sub>{μ<sub>3</sub>-O<sub>3</sub>P(OSiMe<sub>3</sub>)}<sub>2</sub>{μ<sub>2</sub>-O<sub>2</sub>P(OSiMe<sub>3</sub>)<sub>2</sub>}<sub>2</sub>{OP(OSiMe<sub>3</sub>)<sub>3</sub>}] (<b>6</b>), while by adding first the Hhfacac and using
3 equiv of OP(OH)(OSiMe<sub>3</sub>)<sub>2</sub> we isolate [Al{Al(hfacac)}<sub>2</sub>{μ<sub>3</sub>-O<sub>3</sub>P(OSiMe<sub>3</sub>)}<sub>2</sub>{μ<sub>2</sub>-O<sub>2</sub>P(OSiMe<sub>3</sub>)<sub>2</sub>}<sub>2</sub>H{OP(O)(OSiMe<sub>3</sub>)<sub>2</sub>}<sub>2</sub>] (<b>7</b>). These molecules contain units in their cores
that imitate 4=1 SBU of zeolite frameworks. Reaction with the order
of component mixing <b>1</b>, Hhfacac, OP(OH)(OSiMe<sub>3</sub>)<sub>2</sub> at a 1:2:2 molar ratio lead to formation of a larger
cluster [(Al(AlMe){Al(hfacac)}{μ<sub>3</sub>-O<sub>3</sub>P(OSiMe<sub>3</sub>)}<sub>2</sub>{μ<sub>2</sub>-O<sub>2</sub>P(OSiMe<sub>3</sub>)<sub>2</sub>}<sub>3</sub>)<sub>2</sub>] (<b>8</b>)
containing both S4R and 4=1 structural units. Similarly, Hacac (pentan-2,4-dione)
provides an isostructural [(Al(AlMe){Al(acac)}{μ<sub>3</sub>-O<sub>3</sub>P(OSiMe<sub>3</sub>)}<sub>2</sub>{μ<sub>2</sub>-O<sub>2</sub>P(OSiMe<sub>3</sub>)<sub>2</sub>}<sub>3</sub>)<sub>2</sub>] (<b>9</b>). Both molecules display Al centers in three
different coordination environments
