Synthesis and properties of ladder-type 1,4-dihydro-1,4-phosphasilins

2009 ◽  
Vol 87 (9) ◽  
pp. 1222-1229 ◽  
Author(s):  
Yi Ren ◽  
Thomas Linder ◽  
Thomas Baumgartner
Keyword(s):  
Density Functional ◽  
Small Deviation ◽  
Density Functional Theory Calculations ◽  
Advanced Characterization ◽  
Building Blocks ◽  
Structural Features ◽  
Structure Property ◽  
Electronic Effects ◽  
Phosphorus Species ◽  
Molecular Scaffold

The synthesis and advanced characterization of a series of extended dithieno[2,3-b:3′,2′-e][1,4-dihydro-1,4]phosphasilins is reported, and their suitability as new building blocks for organic electronics is evaluated. Synthesis of basic, as well as benzo-extended dithienophosphasilins, can be achieved using appropriate 2,3-dibromothiophene precursors in a two-step protocol introducing the silicon and phosphorus centers subsequently. Both ladder-type materials show the typical reactivity of trivalent phosphorus species and can quantitatively be converted into the corresponding oxides or gold complexes, the latter exemplified with the basic dithienophosphasilin. Their optoelectronic properties were found to be inferior to those of related dithieno[3,2-b:2′,3′-d]phospholes, indicating a disruption of the π-conjugation in the molecular scaffold. X-ray crystallographic studies revealed that the molecular scaffold is planar in the oxidized benzo-extended material, whereas the basic dithieno materials show some small deviation from planarity. Density functional theory calculations suggest all materials to be planar, with the exception of the benzo-extended trivalent phosphasilin. This structure–property study illustrates that the disruption of the π-conjugation in the molecular scaffold of the extended phosphasilins is exclusively due to the presence of the silicon center and its electronic effects, rather than structural features.

scholarly journals 1,3-Diketone Calix[4]arene Derivatives—A New Type of Versatile Ligands for Metal Complexes and Nanoparticles

Molecules ◽  
2021 ◽  
Vol 26 (5) ◽  
pp. 1214
Author(s):  
Sergey N. Podyachev ◽  
Rustem R. Zairov ◽  
Asiya R. Mustafina
Keyword(s):  
Structural Diversity ◽  
Building Blocks ◽  
Structural Features ◽  
Structure Property ◽  
One Pot ◽  
Arene Ligands ◽  
Structure Property Relationships ◽  
New Type ◽  
Synthetic Routes ◽  
Magnetic Resonance Imaging Mri

The present review is aimed at highlighting outlooks for cyclophanic 1,3-diketones as a new type of versatile ligands and building blocks of the nanomaterial for sensing and bioimaging. Thus, the main synthetic routes for achieving the structural diversity of cyclophanic 1,3-diketones are discussed. The structural diversity is demonstrated by variation of both cyclophanic backbones (calix[4]arene, calix[4]resorcinarene and thiacalix[4]arene) and embedding of different substituents onto lower or upper macrocyclic rims. The structural features of the cyclophanic 1,3-diketones are correlated with their ability to form lanthanide complexes exhibiting both lanthanide-centered luminescence and magnetic relaxivity parameters convenient for contrast effect in magnetic resonance imaging (MRI). The revealed structure–property relationships and the applicability of facile one-pot transformation of the complexes to hydrophilic nanoparticles demonstrates the advantages of 1,3-diketone calix[4]arene ligands and their complexes in developing of nanomaterials for sensing and bioimaging.

scholarly journals Microhydration of ionized building blocks of DNA/RNA: infrared spectra of pyrimidine$$^{+}$$-$$(\hbox {H}_{2}\hbox {O})_{\text {1-3}}$$ clusters

2021 ◽  
Vol 75 (3) ◽  
Author(s):  
Kuntal Chatterjee ◽  
Otto Dopfer
Keyword(s):  
Density Functional ◽  
Size Range ◽  
Density Functional Theory Calculations ◽  
Building Blocks ◽  
Ion Solvation ◽  
Structure Stability ◽  
Consistent Picture ◽  
Three Body ◽  
And Function ◽  
Stable Structures

Abstract Hydration of biomolecules is an important physiological process that governs their structure, stability, and function. Herein, we probe the microhydration structure of cationic pyrimidine (Pym), a common building block of DNA/RNA bases, by infrared photodissociation spectroscopy (IRPD) of mass-selected microhydrated clusters, $$\hbox {Pym}^{+}$$ Pym + -$$\hbox {W}_{n}$$ W n (W=$$\hbox {H}_{2}\hbox {O}$$ H 2 O ), in the size range $$n=1$$ n = 1 –3. The IRPD spectra recorded in the OH and CH stretch range are sensitive to the evolution of the hydration network. Analysis with density functional theory calculations at the dispersion-corrected B3LYP-D3/aug-cc-pVTZ level provides a consistent picture of the most stable structures and their energetic and vibrational properties. The global minima of $$\hbox {Pym}^{+}$$ Pym + -$$\hbox {W}_{n}$$ W n predicted by the calculations are characterized by H-bonded structures, in which the H-bonded $$\hbox {W}_{n}$$ W n solvent cluster is attached to the most acidic C4–H proton of $$\hbox {Pym}^{+}$$ Pym + via a single CH...O ionic H-bond. These isomers are identified as predominant carrier of the IRPD spectra, although less stable local minima provide minor contributions. In general, the formation of the H-bonded solvent network (exterior ion solvation) is energetically preferred to less stable structures with interior ion solvation because of cooperative nonadditive three-body polarization effects. Progressive hydration activates the C4–H bond, along with increasing charge transfer from $$\hbox {Pym}^{+}$$ Pym + to $$\hbox {W}_{n}$$ W n , although no proton transfer is observed in the size range $$n\leqslant $$ n ⩽ 3. The solvation with protic, dipolar, and hydrophilic W ligands is qualitative different from solvation with aprotic, quadrupolar, and hydrophobic $$\hbox {N}_{2}$$ N 2 ligands, which strongly prefer interior ion solvation by $$\uppi $$ π stacking interactions. Comparison of $$\hbox {Pym}^{+}$$ Pym + -W with Pym-W and $$\hbox {H}^{+}$$ H + Pym-W reveals the drastic effect of ionization and protonation on the Pym...W interaction. Graphic Abstract

scholarly journals Spectroscopic identification of fragment ions of DNA/RNA building blocks: the case of pyrimidine

2020 ◽  
Vol 22 (30) ◽  
pp. 17275-17290
Author(s):  
Kuntal Chatterjee ◽  
Otto Dopfer
Keyword(s):  
Density Functional Theory ◽  
Infrared Spectroscopy ◽  
Density Functional ◽  
Density Functional Theory Calculations ◽  
Building Blocks ◽  
Functional Theory ◽  
Fragment Ions ◽  
Sequential Loss ◽  
Spectroscopic Identification

The structure of the predominant fragments of the fundamental pyrimidine cation arising from sequential loss of HCN are identified by infrared spectroscopy of tagged ions and dispersion-corrected density functional theory calculations.

scholarly journals Microhydration of protonated biomolecular building blocks: protonated pyrimidine

2020 ◽  
Vol 22 (23) ◽  
pp. 13092-13107
Author(s):  
Kuntal Chatterjee ◽  
Otto Dopfer
Keyword(s):  
Density Functional Theory ◽  
Infrared Spectroscopy ◽  
Density Functional ◽  
Density Functional Theory Calculations ◽  
Building Blocks ◽  
Protonation Site ◽  
Functional Theory

The protonation site and evolution of the hydration network in microsolvated protonated pyrimidine clusters, H+Pym–(H2O)n with n = 1–4, has been explored by infrared spectroscopy and density functional theory calculations.

scholarly journals Physicochemical Insight into Coordination Systems Obtained from Copper(II) Bromoacetate and 1,10-Phenanthroline

Molecules ◽  
2020 ◽  
Vol 25 (22) ◽  
pp. 5324
Author(s):  
Ewelina Krejner ◽  
Tomasz Sierański ◽  
Marcin Świątkowski ◽  
Marta Bogdan ◽  
Rafał Kruszyński
Keyword(s):  
Density Functional Theory ◽  
Density Functional ◽  
Density Functional Theory Calculations ◽  
Building Blocks ◽  
Radiation Absorption ◽  
Ir Absorption ◽  
Bromoacetic Acid ◽  
Functional Theory ◽  
Hirshfeld Analysis ◽  
Coordination Systems

Two different coordination compounds of copper were synthesized from the same building blocks (1,10-phenanthroline, bromoacetate anions, and copper cations). The synthesis parameters were carefully designed and evaluated to allow the change of the resulting compounds molecular structure, i.e., formation of mononuclear (bromoacetato-O,O’)(bromoacetato-O)aqua(1,10-phenanthroline-N,N’)copper(II) and dinuclear (μ-bromido-1:2κ2)bis(μ-bromoacetato-1κO,2κO’)bis(1,10-phenanthroline-N,N’)dicopper(II) bromoacetate bromoacetic acid solvate. The crystal, molecular and supramolecular structures of the studied compounds were determined and evaluated in Hirshfeld analysis. The UV-Vis-IR absorption and thermal properties were studied and discussed. For the explicit determination of the influence of compounds structure on radiation absorption in UV-Vis range, density functional theory and time-dependent density functional theory calculations were performed.

Development of nonlinear optical materials promoted by density functional theory simulations

2014 ◽  
Vol 28 (27) ◽  
pp. 1430018 ◽  
Author(s):  
Xingxing Jiang ◽  
Lei Kang ◽  
Siyang Luo ◽  
Pifu Gong ◽  
Ming-Hsien Lee ◽  
...  
Keyword(s):  
Density Functional Theory ◽  
Density Functional ◽  
Nonlinear Optical ◽  
Functional Materials ◽  
Dft Method ◽  
Structural Features ◽  
Great Success ◽  
Structure Property ◽  
Functional Theory ◽  
Nlo Property

Nonlinear optical (NLO) crystals are very important optoelectronic functional materials and their developments have significantly contributed to the progress of laser science and technology for decades. In order to explore new NLO crystals with superior performances, it is greatly desirable to understand the intrinsic relationship between the macroscopic optical properties and microscopic structural features in crystals. In this paper, the applications of density functional theory (DFT) method to the elucidation of the structure-property relationship and to the exploration on novel NLO materials in the ultraviolet and infrared spectrum regions are reviewed. The great success in the linear and NLO property predictions has been achieved using the first-principles computational simulations, and the mechanism understanding obtained by various analysis tools can give substantial guidance to the search and design of new NLO crystals.

scholarly journals Complementary Base Lowers the Barrier in SuFEx Click Chemistry for Primary Amine Nucleophiles

2020 ◽  
Author(s):  
Jan-Niclas Luy ◽  
Ralf Tonner
Keyword(s):  
Primary Amine ◽  
Density Functional ◽  
Decomposition Analysis ◽  
Building Blocks ◽  
Energy Decomposition Analysis ◽  
Electronic Effects ◽  
Functional Theory ◽  
Molecular Building Blocks ◽  
Further Development ◽  
Crucial Ingredient

The Sulfur (VI) Fluoride Exchange (SuFEx) reaction is an emerging scheme for connecting molecular building blocks. Due to its broad functional group tolerance and rather stable resulting linkage it is seeing rapid adoption in various fields of chemistry. Still, to date the reaction mechanism is poorly understood which hampers further development. Here, we show that the mechanism of the SuFEx reaction for the prototypical example of methanesulfonyl fluoride reacting with methylamine can be understood as an SN2-type reaction. By analyzing the reaction path with the help of density functional theory in vacuo and under consideration of solvent and co-reactant influence we identify the often used complementary base as crucial ingredient to lower the reaction barrier significantly by increasing the nucleophilicity of the primary amine. With the help of energy decomposition analysis (EDA) at the transition state structures we quantify the underlying stereo-electronic effects and propose new avenues for experimental exploration of the potential of SuFEx chemistry.

scholarly journals Development and Testing of an All-Atom Force Field for Diketopyrrolopyrrole Polymers with Conjugated Substituents

2020 ◽  
Author(s):  
Vivek Sundaram ◽  
Alexey V. Lyulin ◽  
Björn Baumeier
Keyword(s):  
Force Field ◽  
Density Functional ◽  
Density Functional Theory Calculations ◽  
Building Blocks ◽  
Variable Number ◽  
Polymer Chains ◽  
Relaxation Processes ◽  
Polymer Backbone ◽  
Dynamics Simulations ◽  
The Individual

We develop an all-atom force field for a series of diketopyrrolopyrrole polymers with two aromatic pyridine substituents and variable number of pi-conjugated thiophene units in the backbone, used as donor material in organic photovoltaic devices. Available intra-fragment parameterizations of the individual fragment building blocks are combined with inter-fragment bonded and non-bonded parameters explicitly derived from density-functional theory calculations. To validate the force field we perform classical molecular dynamics simulations of single polymer chains with 1, 2, and 3 thiophenes in good and bad solvents, and of melts. We observe the expected dependence of the chain conformation on the solvent quality, with the chain collapsing in water, and swelling in chloroform. The glass transition temperature for the polymer melts is found to be in the range of 340K to 370K. Analysis of the mobility of the conjugated segments in the polymer backbone reveals two relaxation processes: a fast one with a characteristic time at room temperature on the order of 10ps associated with nearly harmonic vibrations and a slow one on the order of 100 associated with temperature activated cis-trans transitions.

scholarly journals Expedient synthesis of E-hydrazone esters and 1H-indazole scaffolds through heterogeneous single-atom platinum catalysis

2019 ◽  
Vol 5 (12) ◽  
pp. eaay1537 ◽  
Author(s):  
Cuibo Liu ◽  
Zhongxin Chen ◽  
Huan Yan ◽  
Shibo Xi ◽  
Kah Meng Yam ◽  
...  
Keyword(s):  
Density Functional ◽  
Stereoselective Synthesis ◽  
Density Functional Theory Calculations ◽  
Building Blocks ◽  
Hydrogenation Reaction ◽  
Biologically Active ◽  
Single Atom ◽  
One Pot ◽  
Platinum Catalysis ◽  
Scalable Synthesis

Unprotected E-hydrazone esters are prized building blocks for the preparation of 1H-indazoles and countless other N-containing biologically active molecules. Despite previous advances, efficient and stereoselective synthesis of these compounds remains nontrivial. Here, we show that Pt single atoms anchored on defect-rich CeO2 nanorods (Pt1/CeO2), in conjunction with the alcoholysis of ammonia borane, promotes exceptionally E-selective hydrogenation of α-diazoesters to afford a wide assortment of N-H hydrazone esters with an overall turnover frequency of up to 566 hours−1 upon reaction completion. The α-diazoester substrates could be generated in situ from readily available carboxylic esters in one-pot hydrogenation reaction. Utility is demonstrated through concise, scalable synthesis of 1H-indazole–derived pharmaceuticals and their 15N-labeled analogs. The present protocol highlights a key mechanistic nuance wherein simultaneous coordination of a Pt site with the diazo N═N and ester carbonyl motifs plays a central role in controlling stereoselectivity, which is supported by density functional theory calculations.

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