Determining hydrogen positions in crystal engineered organic molecular complexes by joint neutron powder and single crystal X-ray diffraction

Schmidtmann, Marc; Coster, Paul L.; Henry, Paul; Ting, Valeska P.; Weller, Mark T.; Wilson, Chick C.

doi:10.1039/c3ce42070a

Cited by 20 publications

(24 citation statements)

References 15 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Unfortunately, the very reason that makes H atoms so central in chemistry—the fact that they have only one electron—makes them very hard to detect with x-rays accurately because x-rays scatter from the electron density ( 6 , 7 ). On the other hand, thermal neutrons diffract strongly from the nuclei of H atoms, which makes them detectable by using nuclear reactors or spallation facilities as radiation sources.…”

Section: Introductionmentioning

confidence: 99%

Hydrogen atoms can be located accurately and precisely by x-ray crystallography

et al. 2016

View full text Add to dashboard Cite

show abstract

Section: Introductionmentioning

confidence: 99%

Hydrogen atoms can be located accurately and precisely by x-ray crystallography

et al. 2016

View full text Add to dashboard Cite

show abstract

“…The overall profile fit for the NPD data from the refined model is of good quality (Figure 7). A similar study of the proton transfer and polymorphism in lutidine-pentachlorophenol (PCP) complexes has also yielded similarly promising results, while indicating some of the limits in trying to apply NPD in such complex molecular systems [70]. These hydrogen-bonded molecular complexes again contain SSHBs, and the position of the proton can be tuned by altering the chemistry of the complex (pKamediated proton transfer) or by changing external conditions such as temperature.…”

Section: Polymorphism and Proton Transfer In Molecular Complexesmentioning

confidence: 80%

“…A combination of high resolution X-ray diffraction, single crystal neutron diffraction, charge density and computational approaches established not only the accurate structures of the two forms, but also indicated the energy difference between the polymorphs [69,16]. NPD was thus undertaken on these forms [70] as part of the programme establishing the potential of the technique in the study of hydrogenous molecular systems, since the presence of a short, strong hydrogen bond in the system, and its potential as a possible proton transfer system rendered the accurate determination of the crucial hydrogen atom in the short, strong hydrogen bond (SSHB) important.…”

Section: Polymorphism and Proton Transfer In Molecular Complexesmentioning

confidence: 99%

Neutron powder diffraction – new opportunities in hydrogen location in molecular and materials structure

Wilson¹,

Henry²,

Schmidtmann³

et al. 2014

Crystallography Reviews

Self Cite

View full text Add to dashboard Cite

The potential of neutron powder diffraction in the location of hydrogen atoms in molecular materials and inorganic-molecular complexes is reviewed. Advances in instrumentation and data collection techniques that have made this field accessible are reviewed, along with a wide range of applications carried out by our collaboration investigating functional materials, hydrogen-containing minerals and molecular compounds. Some of the limitations in this area, particularly for molecular systems, are also addressed. IntroductionHydrogen is a key element whose functionality in inorganic material systems stretches from geochemical materials (e.g. clay minerals, cements), through key inorganic compounds (e.g. catalysts, co-ordination complexes and hydroxides/hydrates) and materials (e.g. polymers, hydrogen storage media, proton conductors/fuel cell components) to supramolecular and framework systems (e.g aluminosilicates, solvates and clathrates). The role of hydrogen in the structures (and hence derived applications) of these materials is thus of the utmost importance but one that, until recently, experimental methods generally failed to address, or could only do so in selected cases at great expense and considerable effort.Determination of the position of hydrogen in a material, whether it be a naturally occurring hydrate/hydroxide, a cement, a hydride/hydrogen storage material, a solvate or an organometallic compound has traditionally been difficult, time-consuming, expensive and imprecise, even where possible. However, knowledge of the distribution of hydrogen is central to understanding behaviours such as polymorphism, hydrogen bonding and three-dimensional structure definition, proton diffusion 2 pathways and levels of uptake in hydrogen storage materials, physical properties ranging from ferroelectricity to the elastic properties of polymers, and reaction mechanisms. Therefore the implementation and application of methodology that allows routine hydrogen position definition from readily available material (i.e. small easily synthesised quantities and in polycrystalline/small single crystal (≤50µm) form)is both of widespread application and key importance.In the work described here, development of the application of powder neutron diffraction methods in an optimised fashion to such materials is shown to have the capability to reveal structural information in a range of hydrogen-containing materials. A range of recent studies will be summarized, to illustrate the potential of this new capability. The powerful complementary use of both X-ray and computational methods with neutron powder diffraction in these studies will also be highlighted. The aim in this Review is not to provide a detailed account of the different materials studied, but to highlight the power of the methods of approach we have been systematically developing to access more accurate and different chemistry. It draws on a range of examples from our own collaborative work, which has recently focused on this theme [1].In this review, we have deli...

show abstract

“…The crystal of dph belongs to the monoclinic system with p21/n space group. It is very hard to locate the exact position of hydrogen from single crystal X‐ray diffraction study accurately because a hydrogen has only one electron and since X‐rays are scattered from the electron density . Fortunately, a Q peak is found at the phenolic hydrogen position which is assigned as hydrogen atom rather than the normal fixing of hydrogen at the calculated position.…”

Section: Resultsmentioning

confidence: 99%

The Colorimetric Signaling of Water Content by a Deprotonated Schiff Base in some Aprotic Organic Solvents

et al. 2020

View full text Add to dashboard Cite

A simple Schiff base, (E)-2-[1-{2-(2,4-dinitrophenyl)hydrazono} ethyl]phenol (Hdph) and its deprotonated form, (E)-1-(2,4dinitrophenyl)-2-{1-(2-hydroxyphenyl)ethylidene} hydrazine-1ide (dph) have been synthesized and characterized by various physicochemical and spectroscopic techniques. Their structures have also been determined by single-crystal X-ray crystallography. The dph has been utilized as a colorimetric probe for the signaling of water content in some water-miscible aprotic organic solvents (acetonitrile and tetrahydrofuran). The dph reveals a pronounced colorimetric behavior in response to the variation of water content in these solvents. Significant changes in UV-visible absorption spectra permit a ratiometric analysis of the signaling behavior. The spectral changes are pronounced for the water content of less than 10 %, which is suitable for the application of dph as a receptor for the determination of water content in binary aqueous organic solvents having lower water content. The limit of detection (LOD) for water content in acetonitrile and tetrahydrofuran is calculated as 0.20 % and 0.28 %, respectively.

show abstract

Determining hydrogen positions in crystal engineered organic molecular complexes by joint neutron powder and single crystal X-ray diffraction

Cited by 20 publications

References 15 publications

Hydrogen atoms can be located accurately and precisely by x-ray crystallography

Hydrogen atoms can be located accurately and precisely by x-ray crystallography

Neutron powder diffraction – new opportunities in hydrogen location in molecular and materials structure

The Colorimetric Signaling of Water Content by a Deprotonated Schiff Base in some Aprotic Organic Solvents

Contact Info

Product

Resources

About