Journal: Crystal Growth & Design

Abbreviation

Cryst. Growth Des.

Publisher

American Chemical Society

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ISSN

1528-7483
1528-7505

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Publications 1 - 10 of 108
  • Structure of Metiram, a Crystalline Zinc Coordination Complex with Amorphous Side Phase
    Item type: Journal Article
    Dinnebier, Robert E.; Seidel, Karsten; Terban, Maxwell W.; et al. (2024)
    Crystal Growth & Design
    Ethylenebis(dithiocarbamates) (EBDTCs) have been extensively used as fungicides in agriculture for nearly 80 years. Modern fungicides based on EBDTCs contain metal ions, such as zinc in Zineb and Metiram, manganese in Maneb, or combinations of both, such as in Mancozeb. Despite being commercially available since the 1940s, the molecular structure of the metal complexes of EBDTCs was not described in detail until the crystal structure of Zineb was published in 2020. Zineb (C₄H₆N₂S₄Zn) is a single-phase crystalline material. In this study, we present a comprehensive multimethod structural characterization of Metiram (C₁₂H₂₇N₉S₁₂Zn₃), which is the active ingredient of Polyram WG, a highly effective and plant-compatible organic contact fungicide. Our findings reveal that Metiram comprises two distinct phases. The primary phase, phase I, of Metiram is ethylenebis(dithiocarbamate) zinc(II) ammine, which constitutes 81 wt % of the material, or three-quarters of EBDTC. It is a zinc-coordinating crystalline phase. The crystal structure of this phase was determined by powder X-ray diffraction, revealing 1D S-shaped chains of EBDTC connected by strongly distorted Zn[NH₃][S₄] tetragonal pyramids. These pyramids share their sulfur atoms, and ammonia molecules occupy the apex of the pyramids, pointing alternately up and down. The secondary phase, phase II, constitutes 19 wt % of the material or one-quarter of EBDTC, and is amorphous. Using a combination of different techniques, including microscopy, diffraction, and spectroscopy, we have concluded that phase II consists of Zn-free EBDTC. We infer that the primary structure of this secondary constituent aligns with previous assumptions, notably the absence of a significant amount of Zn and the presence of disulfide bonds.
  • Solubility Prediction of Organic Molecules with Molecular Dynamics Simulations
    Item type: Journal Article
    Bjelobrk, Zoran; Mendels, Dan; Karmakar, Tarak; et al. (2021)
    Crystal Growth & Design
    We present a molecular dynamics simulation method for the computation of the solubility of organic crystals in solution. The solubility is calculated based on the equilibrium free energy difference between the solvated solute and its crystallized state at the crystal surface kink site. To efficiently sample the growth and dissolution process, we have carried out well-tempered metadynamics simulations with a collective variable that captures the slow degrees of freedom, namely, the solute diffusion to and adsorption at the kink site together with the desolvation of the kink site. Simulations were performed at different solution concentrations using constant chemical potential molecular dynamics, and the solubility was identified at the concentration at which the free energy values between the grown and dissolved kink states were equal. The effectiveness of this method is demonstrated by its success in reproducing the experimental trends of solubility of urea and naphthalene in a variety of solvents.
  • Phase Diagram of a Chiral Substance Exhibiting Oiling Out in Cyclohexane
    Item type: Journal Article
    Codan, Lorenzo; Bäbler, Matthäus Ulrich; Mazzotti, Marco (2010)
    Crystal Growth & Design
  • Supramolecular Synthons
    Item type: Journal Article
    Dunitz, J. D.; Gavezzotti, A. (2012)
    Crystal Growth & Design
  • Statistical Analysis of Series of Detection Time Measurements for the Estimation of Nucleation Rates
    Item type: Journal Article
    Maggioni, Giovanni; Bosetti, Luca; Dos Santos, Elena Laternser; et al. (2017)
    Crystal Growth & Design
  • Accounting for the Presence of Molecular Clusters in Modeling and Interpreting Nucleation and Growth
    Item type: Journal Article
    Ahn, Byeongho; Bosetti, Luca; Mazzotti, Marco (2022)
    Crystal Growth & Design
    The effect of molecular cluster formation on the estimation of kinetic parameters for primary nucleation and growth in different systems has been studied using computationally generated data and three sets of experimental data in the literature. It is shown that the formation of molecular clusters decreases the concentration of monomers and hence the thermodynamic driving force for crystallization, which consequently affects the crystallization kinetics. For a system exhibiting a strong tendency to form molecular clusters, accounting for cluster formation in a kinetic model is critical to interpret kinetic data accurately, for instance, to estimate the specific surface energy γ from a set of primary nucleation rates. On the contrary, for a system with negligible cluster formation, a consideration of cluster formation does not affect parameter estimation outcomes. Moreover, it is demonstrated that using a growth kinetic model that accounts for cluster formation allows the estimation of γ from typical growth kinetic data (i.e., de-supersaturation profiles of seeded batch crystallization), which is a novel method of estimating γ developed in this work. The applicability of the novel method to different systems is proven by showing that the estimated values of γ are closely comparable to the actual values used for generating the kinetic data or the corresponding estimates reported in the literature.
  • Conceptual Validation of Stochastic and Deterministic Methods To Estimate Crystal Nucleation Rates
    Item type: Journal Article
    Deck, Leif-Thore; Mazzotti, Marco (2023)
    Crystal Growth & Design
    This work presents a generalized framework to assess the accuracy of methods to estimate primary and secondary nucleation rates from experimental data. The crystallization process of a well-studied model compound was simulated by means of a novel stochastic modeling methodology. Nucleation rates were estimated from the simulated data through multiple methods and were compared with the true values. For primary nucleation, no method considered in this work was able to estimate the rates accurately under general conditions. Two deterministic methods that are widely used in the literature were shown to overpredict rates in the presence of secondary nucleation. This behavior is shared by all methods that extract rates from deterministic process attributes, as they are insensitive to primary nucleation if secondary nucleation is sufficiently fast. Two stochastic methods were found to be accurate independent of whether secondary nucleation is present, but they underestimated rates in the case where a large number of primary nuclei are formed. We hence proposed a criterion to probe the accuracy of stochastic methods for arbitrary data sets, thus providing the theoretical foundations required for their rational use. Finally, we showed how both primary and secondary nucleation rates can be inferred from the same set of detection time data by combining deterministic and stochastic considerations.
  • Toward a Quantitative Description of Crystal Packing in Terms of Molecular Pairs
    Item type: Journal Article
    Dunitz, J.D.; Gavezzotti, A. (2005)
    Crystal Growth & Design
  • Crystal Growth and Morphology Control of OH1 Organic Electrooptic Crystals
    Item type: Journal Article
    Kwon, Seong-Ji; Jazbinsek, Mojca; Kwon, O-Pil; et al. (2010)
    Crystal Growth & Design
  • Secondary Nucleation by Interparticle Energies. III. Nucleation Rate Model
    Item type: Journal Article
    Ahn, Byeongho; Bosetti, Luca; Mazzotti, Marco (2022)
    Crystal Growth & Design
    A nucleation rate model for describing the kinetics of secondary nucleation caused by interparticle energies (SNIPEs) is derived theoretically, verified numerically, and validated experimentally. The theoretical derivation reveals that the SNIPE mechanism can be viewed as enhanced primary nucleation, i.e., primary nucleation with a lower thermodynamic energy barrier (for nucleation) and a smaller critical nucleus size, both caused by the interparticle interactions and the associated energy between the surface of a seed crystal and a molecular cluster in solution, as shown in part I of this series. In the case of a sufficiently agitated suspension, the model depends on four parameters: two reflecting primary nucleation kinetics and the other two accounting for the intensity and effective spatial range of the interparticle interactions. As a numerical verification of the model, we show that the nucleation kinetics described by the SNIPE rate model is in quantitative agreement with those given by the kinetic rate equation model developed in part II of this series. A sensitivity analysis of the SNIPE rate model is conducted to present the effect of key model parameters on the nucleation kinetics. Moreover, the SNIPE rate model is validated by fitting the model to the time-resolved data of secondary nucleation experiments as well as to two other, well-known secondary nucleation rate models. Importantly, all of the estimated parameter values for the SNIPE model were consistent with the theoretical estimates, while some of the estimated parameter values for one of the well-known secondary nucleation models deviated from the corresponding theoretical values significantly.
Publications 1 - 10 of 108