Publications by authors named "Daniel Decato"

18 Publications

  • Page 1 of 1

Advantages of Organic Halogen Bonding for Halide Recognition.

Supramol Chem 2016 11;28(7-8):665-672. Epub 2015 Dec 11.

Department of Chemistry and Biochemistry, University of Montana, Missoula MT, USA.

The study of hydrogen bonding organocatalysis is rapidly expanding. Much research has been directed at making catalysts more active and selective, with less attention on fundamental design strategies. This study systematically increases steric hindrance at the active site of pH switchable urea organocatalysts. Incorporating strong intramolecular hydrogen bonds from protonated pyridines to oxygen stabilizes the active conformation of these ureas thus reducing the entropic penalty that results from substrate binding. The effect of increasing steric hindrance was studied by single crystal X-ray diffraction and by kinetics experiments of a benchmark reaction.
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http://dx.doi.org/10.1080/10610278.2015.1118101DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8188850PMC
December 2015

Cryptic Biosynthesis of the Berkeleypenostatins from Coculture of Extremophilic sp.

J Nat Prod 2021 05 6;84(5):1656-1665. Epub 2021 May 6.

Coculture fermentation of and yielded berkeleypenostatins A-G (-) as well as the previously reported berkeleylactones A-H, the known macrolide A26771B, citrinin, and patulin. As was true with the berkeleylactones, there was no evidence of the berkeleypenostatins in either axenic culture. The structures were deduced from analyses of spectral data, and the absolute configuration of berkeleypenostatin A () was determined by single-crystal X-ray crystallography. Berkeleypenostatins A () and E () inhibited migration of human pancreatic carcinoma cells (HPAF-II). Both compounds were tested by the NCI Developmental Therapeutics Program. In the NCI 60 cell five-dose screen, berkeleypenostatin E () was the more active of the two, with 1-10 μM total growth inhibition (TGI) of all leukemia cell lines, as well as the majority of colon, CNS, melanoma, ovarian, prostate, renal, and breast cancer cell lines.
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http://dx.doi.org/10.1021/acs.jnatprod.1c00248DOI Listing
May 2021

Theoretical, Solid-State, and Solution Quantification of the Hydrogen Bond-Enhanced Halogen Bond.

Angew Chem Int Ed Engl 2021 02 21;60(7):3685-3692. Epub 2020 Dec 21.

Department of Chemistry and Biochemistry, University of Montana, 32 Campus Drive, Missoula, MT, 59812, USA.

Proximal noncovalent forces are commonplace in natural systems and understanding the consequences of their juxtaposition is critical. This paper experimentally quantifies for the first time a Hydrogen Bond-Enhanced Halogen Bond (HBeXB) without the complexities of protein structure or preorganization. An HBeXB is a halogen bond that has been strengthened when the halogen donor simultaneously accepts a hydrogen bond. Our theoretical studies suggest that electron-rich halogen bond donors are strengthened most by an adjacent hydrogen bond. Furthermore, stronger hydrogen bond donors enhance the halogen bond the most. X-ray crystal structures of halide complexes (X =Br , I ) reveal that HBeXBs produce shorter halogen bonds than non-hydrogen bond analogues. F NMR titrations with chloride highlight that the HBeXB analogue exhibits stronger binding. Together, these results form the foundation for future studies concerning hydrogen bonds and halogen bonds in close proximity.
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http://dx.doi.org/10.1002/anie.202012262DOI Listing
February 2021

Influence and Substituent Effects on the HOMO-LUMO Energy Gap and Stokes Shift in Ru Mono-Diimine Derivatives.

J Mol Struct 2019 Nov 10;1195:620-631. Epub 2019 Jun 10.

Department of Chemistry and Biochemistry, University of Montana, Missoula MT, 59812 U.S.A.

The ground (S) and excited triplet (T) electronic states and corresponding optical spectra of a series of cationic complexes [RuH(CO)L(PPh)] (L=2,2´-bipyridyl) (Rubpy), 4,4´-dicarboxylic-2,2´-bipyridyl (Rudcbpy), bis-4,4'-(N-methylamide)-2,2´-bipyridyl (Rudamidebpy), bis-4,4'-(methyl)-2,2´-bipyridyl (RudMebpy), [Ru(CO)dcbpy(PPh)] (Ru(2CO)dcbpy), and [Ru(H)dcbpy(PPh)] (Ru(2H)dcbpy) have been studied by combined Density Functional/Time-Dependent Density Functional (DFT/TDDFT) techniques using different combinations of DFT exchange-correlation functionals and basis sets. PBE0/LANL2DZ provided more accurate geometries to describe S whereas B3LYP/LANL2DZ predicted spectral energies that correlated better with the available experiment data. The Ru (II) complexes with different substituents emit photons ranging from 560-610 nm in the series RudMebpy, Rubpy, Rudamidebpy, Rudcbpy. The calculations predicted a maximum emission at about 540 nm for the complex constructed from two carbonyl π-acceptors ligands to the dcbpy, while an emission in the far infrared region is calculated when two H σ-donor ligands to the dcbpy. Our calculation results show correlations between HOMO-LUMO energy gap, Stokes shift, and T distortion, which reflect the different effects of electron-withdrawing and donating groups. We proposed that these correlations can be used to predict the photophysical properties for new complexes.
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http://dx.doi.org/10.1016/j.molstruc.2019.06.005DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7449144PMC
November 2019

Anion Influence on the Packing of 1,3-Bis(4-Ethynyl-3-Iodopyridinium)-Benzene Halogen Bond Receptors.

Crystals (Basel) 2019 Oct 11;9(10). Epub 2019 Oct 11.

Department of Chemistry and Biochemistry, University of Montana, 32 Campus Dr, Missoula, MT 59812, USA.

Rigid and directional arylethynyl scaffolds have been widely successful across diverse areas of chemistry. Utilizing this platform, we present three new structures of a dicationic 1,3-bis(4-ethynyl-3-iodopyridinium)-benzene halogen bonding receptor with tetrafluoroborate, nitrate, and hydrogen sulfate. Structural analysis focuses on receptor conformation, anion shape, solvation, and long range packing of these systems. Coupled with our previously reported structures, we conclude that anions can be classified as within this family of halogen bonding receptors. Two kinds of antiparallel dimers are observed for these dicationic receptors. An off-centered species is most frequent, present among geometrically diverse anions, and assorted receptor conformations. In contrast, the centered antiparallel dimers are observed with receptors adopting a bidentate conformation in the solid-state. While anions support the solid-state formation of dimers, the molecular geometry and characteristics (planarity, rigidity, and directionality) of arylethynyl systems increases the likelihood of dimer formation by limiting efficient packing arrangements. The significantly larger cation may have considerable influence on the solid-state packing, as similar cationic arylethynyl systems also display these dimers, suggesting.
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http://dx.doi.org/10.3390/cryst9100522DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7098683PMC
October 2019

Structural and Computational Characterization of a Bridging Zwitterionic-Amidoxime Uranyl Complex.

Org Chem Front 2019 Apr 12;6(7):1038-1043. Epub 2019 Mar 12.

Department of Chemistry and Biochemistry, University of Montana, 32 Campus Drive, Missoula, Montana, United States, 59812.

A bridging (μ) neutral zwitterionic amidoxime binding mode previously unobserved between amidoximes and uranyl is reported and compared to other uranyl amidoxime complexes. Density functional theory computations show the dinuclear complex exhibits a shallow potential energy surface allowing for facile inclusion of a nonbonding water molecule in the solid-state.
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http://dx.doi.org/10.1039/C9QO00267GDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6510399PMC
April 2019

A Long-Lived Halogen-Bonding Anion Triple Helicate Accommodates Rapid Guest Exchange.

Angew Chem Int Ed Engl 2018 Dec 8;57(49):16109-16113. Epub 2018 Nov 8.

Department of Chemistry and Biochemistry, University of Montana, 32 Campus Drive, Missoula, MT, 59812, USA.

Anion-templated helical structures are emerging as a dynamic and tractable class of supramolecules that exhibit anion-switchable self-assembly. We present the first kinetic studies of an anion helicate by utilizing halogen-bonding m-arylene-ethynylene oligomers. These ligands formed high-fidelity triple helicates in solution with surprisingly long lifetimes on the order of seconds even at elevated temperatures. We propose an associative ligand-exchange mechanism that proceeded slowly on the same timescale. In contrast, intrachannel anion exchange occurred rapidly within milliseconds or faster as determined by stopped-flow visible spectroscopy. Additionally, the helicate accommodated bromide in solution and the solid state, while the thermodynamic stability of the triplex favored larger halide ions (bromide≈iodide≫chloride). Taken together, we elucidate a new class of kinetically stable helicates. These anion-switchable triplexes maintain their architectures while accommodating fast intrachannel guest exchange.
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http://dx.doi.org/10.1002/anie.201810415DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6449053PMC
December 2018

Correction: The intramolecular hydrogen bonded-halogen bond: a new strategy for preorganization and enhanced binding.

Chem Sci 2018 08 24;9(30):6451. Epub 2018 Jul 24.

University of Montana , 32 Campus Drive , Missoula , MT , USA . Email:

[This corrects the article DOI: 10.1039/C8SC01973H.].
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http://dx.doi.org/10.1039/c8sc90145gDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6115639PMC
August 2018

The intramolecular hydrogen bonded-halogen bond: a new strategy for preorganization and enhanced binding.

Chem Sci 2018 Jul 21;9(26):5828-5836. Epub 2018 Jun 21.

University of Montana , 32 Campus Drive , Missoula , MT , USA . Email:

Natural and synthetic molecules use weak noncovalent forces to preorganize structure and enable remarkable function. Herein, we introduce the intramolecular hydrogen bonded-halogen bond (HB-XB) as a novel method to preorganize halogen bonding (XBing) molecules, while generating a polarization-enhanced XB. Positioning a fluoroaniline between two iodopyridinium XB donors engendered intramolecular hydrogen bonding (HBing) to the electron-rich belt of both XB donors. NMR solution studies established the efficacy of the HB-XB. The receptor with HB-XBs () displayed a nearly 9-fold increase in halide binding over control receptors. Gas-phase density functional theory conformational analysis indicated that the amine stabilizes the bidentate conformation. Furthermore, gas-phase interaction energies showed that the bidentate HB-XBs of are more than 3.2 kcal mol stronger than the XBs in a control without the intramolecular HB. Additionally, crystal structures confirm that HB-XBs form tighter contacts with I and Br and produce receptors that are more planar. Collectively the results establish the intramolecular HB-XB as a tractable strategy to preorganize XB molecules and regulate XB strength.
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http://dx.doi.org/10.1039/c8sc01973hDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6050591PMC
July 2018

The synthesis of lactone-bridged 1,3,5-triphenylbenzene derivatives as pi-expanded coumarin triskelions.

Tetrahedron Lett 2017 12 6;58(50):4703-4708. Epub 2017 Nov 6.

Department of Chemistry, University of Wisconsin-Eau Claire, Eau Claire, WI, 54702, United States.

Two triply lactone-bridged 1,3,5-triphenylbenzene derivatives with solubilizing moieties have been synthesized in five and six steps from commercially available starting materials. Compounds containing the 1,3,5-triphenylbenzene core with two atom bridges are relatively unknown. This new class of pi-expanded coumarins contain triskelion architectures and X-ray crystallographic studies of one of the triskelions indicates that the 1,3,5-triphenylbenzene core adopts a near-planar geometry. This is the only known example of a two atom-bridged 1,3,5-triphenylbenzene derivative to adopt a planar structure.
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http://dx.doi.org/10.1016/j.tetlet.2017.11.010DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5804744PMC
December 2017

Steric Effects of pH Switchable, Substituted (2-pyridinium)urea Organocatalysts: a Solution and Solid Phase Study.

Supramol Chem 2018 11;30(12):1004-1010. Epub 2018 Sep 11.

Department of Chemistry and Biochemistry, University of Montana, Missoula MT, USA.

The study of hydrogen bonding organocatalysis is rapidly expanding. Much research has been directed at making catalysts more active and selective, with less attention on fundamental design strategies. This study systematically increases steric hindrance at the active site of pH switchable urea organocatalysts. Incorporating strong intramolecular hydrogen bonds from protonated pyridines to oxygen stabilizes the active conformation of these ureas thus reducing the entropic penalty that results from substrate binding. The effect of increasing steric hindrance was studied by single crystal X-ray diffraction and by kinetics experiments of a benchmark reaction.
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http://dx.doi.org/10.1080/10610278.2018.1515488DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6510400PMC
September 2018

Experimental investigation of halogen-bond hard-soft acid-base complementarity.

Acta Crystallogr B Struct Sci Cryst Eng Mater 2017 Apr 29;73(Pt 2):203-209. Epub 2017 Mar 29.

Department of Chemistry and Biochemistry, University of Montana, 32 Campus Dr, Missoula, MT 59812, USA.

The halogen bond (XB) is a topical noncovalent interaction of rapidly increasing importance. The XB employs a `soft' donor atom in comparison to the `hard' proton of the hydrogen bond (HB). This difference has led to the hypothesis that XBs can form more favorable interactions with `soft' bases than HBs. While computational studies have supported this suggestion, solution and solid-state data are lacking. Here, XB soft-soft complementarity is investigated with a bidentate receptor that shows similar associations with neutral carbonyls and heavy chalcogen analogs. The solution speciation and XB soft-soft complementarity is supported by four crystal structures containing neutral and anionic soft Lewis bases.
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http://dx.doi.org/10.1107/S2052520617001809DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6688566PMC
April 2017

The Berkeleylactones, Antibiotic Macrolides from Fungal Coculture.

J Nat Prod 2017 04 22;80(4):1150-1160. Epub 2017 Mar 22.

Center for Biomolecular Sciences, College of Pharmacy, University of Illinois at Chicago , Chicago, Illinois 60607, United States.

A carefully timed coculture fermentation of Penicillium fuscum and P. camembertii/clavigerum yielded eight new 16-membered-ring macrolides, berkeleylactones A-H (1, 4, 6-9, 12, 13), as well as the known antibiotic macrolide A26771B (5), patulin, and citrinin. There was no evidence of the production of the berkeleylactones or A26771B (5) by either fungus when grown as axenic cultures. The structures were deduced from analyses of spectral data, and the absolute configurations of compounds 1 and 9 were determined by single-crystal X-ray crystallography. Berkeleylactone A (1) exhibited the most potent antimicrobial activity of the macrolide series, with low micromolar activity (MIC = 1-2 μg/mL) against four MRSA strains, as well as Bacillus anthracis, Streptococcus pyogenes, Candida albicans, and Candida glabrata. Mode of action studies have shown that, unlike other macrolide antibiotics, berkeleylactone A (1) does not inhibit protein synthesis nor target the ribosome, which suggests a novel mode of action for its antibiotic activity.
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http://dx.doi.org/10.1021/acs.jnatprod.7b00133DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5467647PMC
April 2017

A Halogen-Bond-Induced Triple Helicate Encapsulates Iodide.

Angew Chem Int Ed Engl 2016 09 14;55(40):12398-402. Epub 2016 Jul 14.

Department of Chemistry and Biochemistry, University of Montana, 32 Campus Dr, Missoula, MT, 59812, USA.

The self-assembly of higher-order anion helicates in solution remains an elusive goal. Herein, we present the first triple helicate to encapsulate iodide in organic and aqueous media as well as the solid state. The triple helicate self-assembles from three tricationic arylethynyl strands and resembles a tubular anion channel lined with nine halogen bond donors. Eight strong iodine⋅⋅⋅iodide halogen bonds and numerous buried π-surfaces endow the triplex with remarkable stability, even at elevated temperatures. We suggest that the natural rise of a single-strand helix renders its linear halogen-bond donors non-convergent. Thus, the stringent linearity of halogen bonding is a powerful tool for the synthesis of multi-strand anion helicates.
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http://dx.doi.org/10.1002/anie.201605440DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5155591PMC
September 2016

Crystal structure of [1,1':3',1''-ter-phenyl]-2',3,3''-tri-carb-oxy-lic acid.

Acta Crystallogr E Crystallogr Commun 2015 Sep 22;71(Pt 9):o667-8. Epub 2015 Aug 22.

Department of Chemistry and Biochemistry, University of Montana, 32 Campus Dr., Missoula, Montana 59812, USA.

The asymmetric unit of the title compound, C21H14O6, com-prises two symmetrically independent mol-ecules that form a locally centrosymmetric hydrogen-bonded dimer, with the planes of the corresponding carb-oxy-lic acid groups rotated by 15.8 (1) and 17.5 (1)° relative to those of the adjacent benzene rings. The crystal as a whole, however, exhibits a noncentrosymmetric packing, described by the polar space group Pca21. The dimers form layers along the ab plane, being inter-connected by hydrogen bonds involving the remaining carb-oxy-lic acid groups. The plane of the central carb-oxy-lic acid group forms dihedral angles of 62.5 (1) and 63.0 (1)° with those of the adjacent benzene rings and functions as a hydrogen-bond donor and acceptor. As a donor, it inter-connects adjacent layers, while as an acceptor it stabilizes the packing within the layers. The 'distal' carb-oxy-lic acid groups are nearly coplanar with the planes of the adjacent benzene rings, forming dihedral angles of 1.8 (1) and 7.1 (1)°. These groups also form intra- and inter-layer hydrogen bonds, but with 'reversed' functionality, as compared with the central carb-oxy-lic acid groups.
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http://dx.doi.org/10.1107/S2056989015015029DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4555404PMC
September 2015

Crystal structure and absolute configuration of preaustinoid A1.

Acta Crystallogr E Crystallogr Commun 2015 Aug 22;71(Pt 8):o596-7. Epub 2015 Jul 22.

Department of Chemistry and Biochemistry, University of Montana, 32 Campus Drive, Missoula, Montana 59812, USA.

The absolute structure of the title compound preaustinoid A1 [systematic name: (5aR,7aS,8R,10S,12R,13aR,13bS)-methyl 10-hy-droxy-5,5,7a,10,12,13b-hexa-methyl-14-methyl-ene-3,9,11-trioxohexa-deca-hydro-8,12-methano-cyclo-octa-[3,4]benzo[1,2-c]oxepine-8-carboxyl-ate], C26H36O7, has been determined by resonant scattering using Cu Kα radiation [Flack parameter = 0.07 (15)]. The structure is consistent with that reported previously [Stierle et al. (2011). J. Nat. Prod. 74, 2272-2277], determined by detailed analysis of MS and NMR data. The mol-ecule consists of a fused four-ring arrangement. The seven-membered oxepan-2-one ring has a chair conformation, as do the central cyclo-hexane rings, while the outer cyclo-hexa-1,3-dione ring has a boat conformation. In the crystal, mol-ecules are linked via O-H⋯O hydrogen bonds, forming helical chains propagating along [100].
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http://dx.doi.org/10.1107/S2056989015013614DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4571416PMC
August 2015

Redetermination and absolute configuration of berkeleydione.

Acta Crystallogr E Crystallogr Commun 2015 Apr 21;71(Pt 4):o248. Epub 2015 Mar 21.

Department of Biological and Pharmaceutical Sciences, University of Montana, 32 Campus Dr., Missoula, Montana 59812, USA.

The crystal structure of the title compound, berkeleydione [systematic name; (5aS,7R,9S,11R,11aS)-methyl 9-hy-droxy-1,1,5,7,9,11a-hexa-methyl-14-methyl-idene-3,8,10-trioxo-1,3,4,5a,6,7,8,9,10,11,11a,12-dodeca-hydro-7,11-methano-cycloocta-[4,5]cyclo-hepta-[1,2-c]pyran-11-carboxyl-ate], C26H32O7, has been reported previously [Stierle et al. (2004 ▶). Org. Lett. 6, 1049-1052]. However, the absolute configuration could not be determined from the data collected with Mo Kα radiation and has now been determined by refinement of the Flack parameter with data collected using Cu Kα radiation. It is in agreement with the previous circular dichroism assignment, and the crystal packing is similar to that described previously.
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http://dx.doi.org/10.1107/S2056989015003965DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4438833PMC
April 2015

Solution and solid-phase halogen and C-H hydrogen bonding to perrhenate.

Chem Commun (Camb) 2015 Jan;51(8):1417-20

Department of Chemistry, University of Montana, 32 Campus Dr., Missoula, MT 59812, USA.

(1)H NMR spectroscopic and X-ray crystallographic investigations of a 1,3-bis(4-ethynyl-3-iodopyridinium)benzene scaffold with perrhenate reveal strong halogen bonding in solution, and bidentate association in the solid state. A nearly isostructural host molecule demonstrates significant C-H hydrogen bonding to perrhenate in the same phases.
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http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5065062PMC
http://dx.doi.org/10.1039/c4cc09242bDOI Listing
January 2015