Diisopropylammonium Chloride Research Articles

SHG Assisted Mixed-Phases Anatomizing in a Molecular Ferroelectric.

Anatomizing mixed-phases, referring to analyzing the mixing profiles and quantifying the phases' proportions in a material, which is of great significance in the genuine applications. Here, by using second-harmonic generation (SHG)polarimetry and piezoresponse force microscopy (PFM) techniques, this work elucidates the contributions and distributions of two different symmetric phases mixed in an archetype monoaxial molecular ferroelectric, diisopropylammonium chloride (DIPACl). The two competing phases are preferred in thermodynamics or kinetic process respectively, and this work evidences the switching behavior between the two competing phases facilitated by an external electrical field as opposed to a heating process. This research contributes novel insights into phase engineering in the field of molecular ferroelectrics and is poised to serve as a potent analytical tool for subsequent applications.

Physicochemical Properties of Organic Molecular Ferroelectric Diisopropylammonium Chloride Thin Films.

We fabricated ferroelectric films of the organic molecular diisopropylammonium chloride (DIPAC) using the dip-coating technique and characterized their properties using various methods. Fourier-transform infrared, scanning electron microscopy, and X-ray diffraction analysis revealed the structural features of the films. We also performed ab-initio calculations to investigate the electronic and polar properties of the DIPAC crystal, which were found to be consistent with the experimental results. In particular, the optical band gap of the DIPAC crystal was estimated to be around 4.5 eV from the band structure total density-of-states obtained by HSE06 hybrid functional methods, in good agreement with the value derived from the Tauc plot analysis (4.05 ± 0.16 eV). The films displayed an island-like morphology on the surface and showed increasing electrical conductivity with temperature, with a calculated thermal activation energy of 2.24 ± 0.03 eV. Our findings suggest that DIPAC films could be a promising alternative to lead-based perovskites for various applications such as piezoelectric devices, optoelectronics, sensors, data storage, and microelectromechanical systems.

Dielectric, impedance, modulus spectroscopy and AC conductivity studies on novel organic ferroelectric diisopropylammonium chloride (dipaCl)

Organic molecular ferroelectric diisopropylammonium chloride (dipaCl) was successfully synthesized using diisopropylamine, hydrochloric acid (57%) and methanol solution. Dielectric permittivity, impedance, modulus spectroscopy and conductivity were systematically studied by Capacitance–Conductance ([Formula: see text] – [Formula: see text] measurements in the temperature range of 373–445 K. Dielectric property tests clearly show that the organic molecular ferroelectric dipaCl obeys Curies–Weiss law 1/[Formula: see text] = ([Formula: see text]–[Formula: see text]/[Formula: see text]. The real ([Formula: see text] and imaginary ([Formula: see text]) parts of the electrical modulus were calculated from the various values of [Formula: see text] and [Formula: see text]. It is shown that AC conductivity satisfies the relation [Formula: see text], where the power exponent [Formula: see text] depends on temperature and frequency. From Arrhenius equation, the activation energies [Formula: see text]and [Formula: see text] are also calculated which describes the complete conduction mechanism of dipaCl.

Electric Interactions in Mixtures of Ferroelectric Powders of Diisopropylammonium Chloride and Lead Titanate

Electric Interactions in Mixtures of Ferroelectric Powders of Diisopropylammonium Chloride and Lead Titanate

Crystal structure, hirshfeld surface analysis and phase transformation behaviour of diisopropylammonium chloride hemihydrate crystals

The phase stability of the rarely studied diisopropylammonium chloride hemihydrate (DPC-HH) was investigated in a range of temperature from 100 K to 503 K. The single crystals of DPC-HH grown from methanol solution belong to orthorhombic crystal system with space group Ccca at ambient conditions (296 K) and do not show any phase transformation till 100 K upon cooling whereas it is physically less stable when stored at room temperature due to host-guest nature of the diisopropylammonium chloride (DPC) and water in the DPC-HH lattices. While heating above room temperature dehydration of the hydrate molecules occurs which leads to the crystallization of anhydrous DPC in monoclinic crystal system with space group P21 at 342 K and further at 439.7 K the DPC undergoes a ferroelectric to paraelectric phase transition through a structural transformation from monoclinic P21 to P21/m which is reversible. The Hirshfeld surface and fingerprint plots were used to study the intermolecular interactions of DPC-HH. The intermolecular H⋯H contacts was most significant interactions present in the crystal with over 72% of the total Hirshfeld surface. Powder X-ray diffraction, Raman and FT-IR spectroscopy, TGA and DSC techniques were employed to monitor and confirm the phase stability of DPC-HH crystals and ferro-para transformations occur in the DPC crystal system.

Structural Evolution of Diisopropylammonium Chloride (DIPAC) Molecular Ferroelectric

Room-temperature changes in the structure of a new diisopropylammonium chloride (C6H16ClN, DIPAC) molecular ferroelectric have been investigated by high-resolution cross polarization/magic-angle spinning nuclear magnetic resonance (CP/MAS NMR) and X-ray diffraction (XRD) methods. The NMR measurements are carried out using 13C nuclei. Depending on time and heat treatment, monoclinic ferroelectric or orthorhombic nonpolar phases (as well as their coexistence) are observed. It is shown that the polar DIPAC modification at room temperature is transformed in the course of time into the nonpolar orthorhombic structure.

Структурная эволюция молекулярного сегнетоэлектрика хлорида диизопропиламмония (DIPAC)

Changes in structure of a new molecular ferroelectric diisopropylammonium chloride (C6H16ClN, DIPAC) at room temperature were studied by high-resolution (CP-MAS) nuclear magnetic resonance (NMR) and X-ray analysis. NMR measurements were carried out for ^{13}С nuclei. Monoclinic ferroelectric and orthorhombic nonpolar phases as well as their coexistence were observed depending on time and thermal treatment. It was shown that the polar modification of DIPAC at room temperature transforms with time to the nonpolar orthorhombic structure. N. I. Uskova, E. V. Charnaya, L. Yu. Podorozhkin, S. V. Baryshnikov, I. V. Egorova, A. Yu. Milinskii

13C NMR of DIPAC and DIPAB organic ferroelectrics

The diisopropylammonium chloride (C6H16ClN, DIPAC) and diisopropylammonium bromide (C6H16BrN, DIPAB) molecular crystals are recently discovered ferroelectrics with sufficiently high spontaneous polarization and Curie temperature. We performed first studies of these crystals by 13C NMR. CP MAS spectra were collected within large temperature ranges covering the Curie points. The reconstructive phase transition from the initial orthorhombic P212121 structure of DIPAB to the monoclinic ferroelectric P21 structure leads to an abrupt alteration in the 13C spectrum. The 13C spectra for DIPAC and DIPAB in the ferroelectric P21 phase are quite similar with four lines at lower frequencies, which correspond to the CH3 groups, and two lines with close chemical shifts, which correspond to two CH groups. The transition into the paraphase leads to gradual reduction of the interline distances in the low-frequency quadruplet and in the doublet. The step-like changes in the interline frequency shifts at this transition indicating its first order. The analysis of the spectrum evolution in the paraphase shows that only a CH group lays in the reflection plane above the P21 → P21/m transition, while the second CH group only moves closer to the reflection plane upon further heating.

Molecular dynamics simulations of ferroelectricity in di-isopropyl-ammonium halide molecular crystals

Ferroelectric molecular crystals are a promising class of materials with lower cost and environment-friendly preparation process. In this work, by combining first-principles calculations and molecular dynamics simulations, we report a systematic study of of ferroelectricity in three molecular ferroelectrics: di-isopropyl-ammonium chloride (DIPAC), di-isopropyl-ammonium bromide (DIPAB) and di-isopropyl-ammonium iodide (DIPAI). Our results agree with previous electronic structure calculations and provide new insights into the mechanism of the phase transition.

Impact of nanoconfinement on the diisopropylammonium chloride (C6H16ClN) organic ferroelectric

ABSTRACTThe dielectric studies of diisopropylammonium chloride (DIPAC) nanoparticles embedded into opal and MCM-41 silica matrices are presented. It is shown that the ferroelectric phase transition shifts to low temperatures and broadens for DIPAC within the opal pores compared to bulk. The thermal hysteresis of the transition increases under opal nanoconfinement. No anomalies of the permittivity relevant to the ferroelectric transition are observed for DIPAC within the MCM-41 molecular sieves likely due to formation of the amorphous phase.

NMR and NQR Study of Above-Room-Temperature Molecular Ferroelectrics Diisopropylammonium Chloride and Diisopropylammonium Perchlorate

The phase transitions and molecular motions in organic ferroelectrics diisopropylammonium chloride and diisopropylammonium perchlorate have been studied by proton NMR and spin–lattice relaxation and by 14N NQR and spin–lattice relaxation. In diisopropylammonium chloride, proton T1 shows slowing of the reorientation of methyl groups and a discontinuous decrease at the ferroelectric to paraelectric phase transition. The 14N NQR frequencies are observed in the range characteristic for a C–NH2+–C ion. Diisopropylammonium perchlorate undergoes three phase transitions at varying temperatures. Proton and 14N T1 shows the presence of two slow motions: the reorientation of the methyl groups and a second slow motion in phases II and III which is most probably tumbling of diisopropylammonium ions. The discontinuous change of proton T1 and M2 at the ferroelectric to paraelectric phase transition is ascribed to exchange between two orientations of a diisopropylammonium ion in the paraelectric phase. The 14N quadrupole...

Statics and Dynamics of Ferroelectric Domains in Diisopropylammonium Bromide.

An electrically written domain structure formed by a biased tip, and visualized in the piezoresponse force microscopy mode, shows stable charged domain walls in the organic ferroelectric diisopropylammonium chloride microcrystal.

Diisopropylammonium Chloride: A Ferroelectric Organic Salt with a High Phase Transition Temperature and Practical Utilization Level of Spontaneous Polarization

A simple organic salt, diisopropylammonium chloride, shows the highest ferroelectric phase transition temperature among molecule-based ferroelectrics with a large spontaneous polarization, making it a candidate for practical technological applications.

A Facile Synthesis of Carbamoylsilanes, ‐boranes and ‐phosphane Oxides – Isolation of the First Uncomplexed Carbamoylborane

C-(Trimethylsilyloxy)-, C-(triisopropylsilyloxy)-, C-(diphenylboryloxy), C-[bis(diisopropylamino)boryloxy]- and C-(di-tert-butylphosphoryloxy)-N,N-diisopropylaldiminium salts are readily prepared in good to excellent yields from either diisopropylformamide or (chloromethylene)diisopropylammonium chloride. Deprotonation of these aldiminium salts leads to transient (amino)(oxy)carbenes, which cleanly rearrange to carbamoyl derivatives. This synthetic methodology gives access to sterically hindered carbamoylsilanes, -boranes and phosphane oxides that are hardly accessible by other routes.

Constructing co-crystals with molecular sense and supramolecular sensibility

Themore than 365,000 organic and organometallic small-molecule crystal structures in the Cambridge Structural Database (CSD) are a good source of data for understanding the crystal structures of solvates. It is trivial with the existing search software [1] to find all CSD entries containing a particular solvent, say water, and a survey of the 50most common solvents in the CSD has been published [2]. It might be interesting, however, to know if any of these solvates also exist in an unsolvated form; given a crystal structure of di-isopropylammonium chloride hydrate in the CSD, for example, one could wonder if a crystal structure of di-isopropylammonium chloride itself is present in the database. A computer program was written that for a given solvent molecule finds all pairs of solvated versus unsolvated CSD entries; a list of solvate structures for which no unsolvated form exists in the CSD is also generated. These lists enable us to examine if properties such as the number of hydrogen-bond donors / acceptors or the molecular flexibility influence solvate formation. Results for hydrates will be presented.

Searching the Cambridge Structural Database for solvatedvsunsolvated pairs

The more than 365,000 organic and organometallic small-molecule crystal structures in the Cambridge Structural Database (CSD) are a good source of data for understanding the crystal structures of solvates. It is trivial with the existing search software [1] to find all CSD entries containing a particular solvent, say water, and a survey of the 50 most common solvents in the CSD has been published [2]. It might be interesting, however, to know if any of these solvates also exist in an unsolvated form; given a crystal structure of di-isopropylammonium chloride hydrate in the CSD, for example, one could wonder if a crystal structure of di-isopropylammonium chloride itself is present in the database. A computer program was written that for a given solvent molecule finds all pairs of solvated versus unsolvated CSD entries; a list of solvate structures for which no unsolvated form exists in the CSD is also generated. These lists enable us to examine if properties such as the number of hydrogen-bond donors / acceptors or the molecular flexibility influence solvate formation. Results for hydrates will be presented.

Diisopropylammonium chloride hemihydrate, a combined single-crystal and powder diffraction study

By the reaction of diiso­propyl­amine (dip) with hydro­chloric acid and crystallization at room temperature, dipHCl, known from the literature, and the corresponding hemihydrate, C6H16N+·Cl−·0.5H2O or dipHCl·0.5H2O, have been obtained. By using a new humidity chamber for the powder diffraction study it has been proven that dipHCl reacts via a solid-solid phase transition to give dipHCl·0.5H2O on increasing the relative humidity of the sample atmosphere. The cations and anions are connected by hydrogen bonds to form chains along the crystallographic [100] direction. The extended polymeric zigzag chains form layers in the ac plane, separated by water mol­ecules. The cations and water molecules lie on crystallographic twofold rotation axes.

(2-Hydroxyethyl)diisopropylammonium chloride and its derivatives

The crystal structure of the title compound, C 8 H 20 NO + .Cl - , (I), and the structures of its derivatives, (2-chloroethyl)diisopropylammonium chloride, C 8 H 19 ClN + .Cl - , (II), and diisopropyl(2-mercaptoethyl)ammonium chloride, C 8 H 20 NS + .Cl - , (III), are described. The conformations of the isopropyl groups in (II) (gauche-gauche) are different from those in (I) and (III) (both gauche-trans). The structures are stabilized by hydrogen bonds of the type Y-H…Cl (Y = N, O, S) and C-H…X (X = Cl, S).

Synthesis of phosphoranes by using N-chlorodi-isopropylamine

A wide range of cyclic and acyclic tervalent phosphorus compounds condense with 1,2- or 1,3-glycols, or with catechols, in the presence of N-chlorodi-isopropylamine, to give di-isopropylammonium chloride and the corresponding cyclic phosphoranes containing 1,3,2-dioxaphospholan or 1,3,2-dioxaphosphorinan rings. The variable-temperature n.m.r. spectra of a number of the new phosphoranes are recorded and interpreted in accord with previous data on relative apicophilicities of groups and ring-strain effects.