Complexation of biologically essential (mono- and divalent) metal cations to cucurbiturils: a DFT/SMD evaluation of the key factors governing the host–guest recognition

Abstract

Interaction between CB[n] (n = 5–8) and biologically essential mono- and divalent metal cation.

Complexation of trivalent metal cations (Al3+, Ga3+, In3+, La3+, Lu3+) to cucurbiturils: a DFT/SMD evaluation of the key factors governing the host–guest recognition

“…This research is a logical continuation of an earlier study on the interaction between CB[n]s (n = 5, 6, 7 and 8) and a series of biologically essential mono-and divalent metal cations (Na + /K + and Mg 2+ /Ca 2+ , respectively). 1 The results obtained for these metal ions indicated a well-defined preference towards small and highly charged metals, as magnesium is the one that stands out from all the rest (Na + , K + and Ca 2+ ) when comparing the Gibbs energy values. 1 The series of group IIIA (Al 3+ , Ga 3+ and In 3+ ) and lanthanide (La 3+ , Lu 3+ ) metal cations have been chosen for the task as they allow us to assess, in addition to the Na + /K + and Mg 2+ /Ca 2+ series, the effect of various metal parameters (variable charge, ionic radius, coordination number, degree of solvation) on the strength and form of the interactions with the host CB[n]s.…”

“…Note that changing the temperature and external pressure applied to the system has negligible effect on the evaluated free energies of the complex formation reactions. 1 Solvation effects were accounted for by employing the SMD (Density-based Solvation Model) method 28 as implemented in the Gaussian 09 suite of programs. 29 For each optimized molecule/complex in the gas phase, a single point calculation in water (dielectric constant e = 78) was performed at the same level of theory.…”

Host–Guest Complexation of Cucurbit[7]Uril and Cucurbit[8]Uril with the Antineoplastic and Multiple Sclerosis Agent Mitoxantrone (Novantrone)

“…This method/ basis set combination has been recently shown to be reliable in predicting the complex formation between CBs and simple metal cations. 36 The optimized structures were subjected to a frequency analysis at the same level of theory to confirm the absence of negative (imaginary) frequencies. Single-point calculations were performed at the M062X/6-31+G(d,p) level of theory.…”

DFT-D4 Insight into the Inclusion of Amphetamine and Methamphetamine in Cucurbit[7]uril: Energetic, Structural and Biosensing Properties

“…Among them, cucurbiturils are a relatively novel family of barrelshaped macrocyclic hosts that can encapsulate guest molecules in their unique large cavities, which are edged by carbonyl oxygen atoms [19][20][21]. Cucurbiturils can be synthesized in a variety of different morphology sizes, with either 5, 6, 7, 8 or 10 glycoluril subunits [21][22][23][24]. In recent years, cucurbit[n]urils (CB[n]) were used as drug delivery vehicles for neutral molecules and cations due to their high affinity to form host-guest inclusion complexes [25][26][27].…”