The stable polyiodides: Experimental and theoretical studies of formation mechanism

Wang, Yuan; Xue, Yongqiang; Wang, Xueping; Cui, Zixiang; Wang, Leilei

doi:10.1016/j.molstruc.2014.05.062

“…[26] Single-crystald iffraction measurements:Aprismaticc rystal of TEAI of 200 100 30 mm 3 was loaded in aM errill-Bassett DAC, equipped with 0.5 mm diamond and steel gaskets.Nitrogen was used as ap ressure-transmitting medium, and the pressure was calibrated with ruby fluorescence. [26] Single-crystald iffraction measurements:Aprismaticc rystal of TEAI of 200 100 30 mm 3 was loaded in aM errill-Bassett DAC, equipped with 0.5 mm diamond and steel gaskets.Nitrogen was used as ap ressure-transmitting medium, and the pressure was calibrated with ruby fluorescence.…”

Section: Methodsmentioning

confidence: 99%

“…TEAI was chosen after extensive screening of the Cambridge Structural Database [24] (entries HALTAP [25] and HALTAP01 [26] )i no rder to find am oiety with appropriate packing,r eady for catenation between donor (I 3 À )a nd acceptor (I 2 )u pon compression. TEAI was chosen after extensive screening of the Cambridge Structural Database [24] (entries HALTAP [25] and HALTAP01 [26] )i no rder to find am oiety with appropriate packing,r eady for catenation between donor (I 3 À )a nd acceptor (I 2 )u pon compression.…”

mentioning

confidence: 99%

Pressure‐Induced Polymerization and Electrical Conductivity of a Polyiodide

Poręba

¹

,

Ernst

²

,

Zimmer³

et al. 2019

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We report the high-pressure structural characterization of an organic polyiodide salt in which ap rogressive addition of iodine to triiodide groups occurs.C ompression leads to the initial formation of discrete heptaiodide units, followed by polymerization to a3Danionic network. Although the structural changes appear to be continuous,t he insulating salt becomes as emiconducting polymer above1 0GPa.T he features of the pre-reactive state and the polymerized state are revealed by analysis of the computed electron and energy densities.T he unusually high electrical conductivity can be explained with the formation of new bonds.Polyiodides (PIs) in crystal form were discovered about 200 years ago. [1] Their structural diversity,which is due to the bonding flexibility of iodine,r emains the subject of continuous interest. [2][3][4] Nowadays,v arious PIs are known, ranging from I 3 À to I 29 3À ,with the general formula I nÀ 2 m+n and n up to 4. Their building blocks consist of I 3 À as adonor and I 2 as an acceptor forming ac harge transfer (CT) complex. CT complexes can interact further to form extended structures with various topologies,u pt oc ubic networks.A st he aggregation of iodine units is somewhat unpredictable,t he design of PIs is not easy.Moreover,the classification of higher units is,thus far,pragmatically based on the distance between iodine atoms,but universal criteria are still lacking.Different theoretical approaches to study bonds in PIs exist, for example,calculations of the potential energy surface and bond order, [5] energy decomposition analysis (EDA), [6] analysis of the electron density and its Laplacian at bond critical points (BCP), [7] theelectron localization function, and the one-electron potential. [8] Furthermore,t he energy den-

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“…Iodine species have a tendency to catenate through donor acceptor interactions. By changing the molar ratio of reactants (I − and I 2 ) in solution salts with various polymerization degrees can be obtained, although some of them are stable only in solutions …”

Section: Introductionmentioning

confidence: 99%

Triiodide Organic Salts: Photoelectrochemistry at the Border between Insulators and Semiconductors

Wlaźlak

¹

,

Kalinowska‐Tłuścik

²

,

Nitek

³

et al. 2018

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The intriguing properties of triiodide organic salts ([(C6H5)3AsO]2H+I3−, (C6H5CH2)3NH+I3− ⋅C6H5CH3, and [(C6H5CH2)3NO]2H+I3−) have been analyzed in detail using experimental and theoretical techniques. The analysis of crystal structures, density of states distribution and photocurrent generation of this purely ionic materials indicates insulating character of the ground state, whereas semiconducting character in higher excited states is observed. These peculiar properties of the studied compounds are the consequence of a specific electronic structure: very flat dispersion diagrams of the valence and conduction band and highly dispersive character on the higher conduction band. Weak triiodide‐triiodide interactions play the key role in the visible absorption range of these salts, while the charge transfer involving high energy carbon‐centered states is responsible for photocurrent generation. The complexity of the electrochemical reactions and the interactions of the I3− anion with light, solubility in organic solvents and the simplicity of preparation make these materials interesting candidates for application in unconventional optoelectronic devices.

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“…In this study, we investigated the response of tetraethylammonium diiodine triiodide (TEAI) to compression by using powder and single‐crystal X‐ray diffraction, electrical conductivity measurements, and first principle calculations. TEAI was chosen after extensive screening of the Cambridge Structural Database (entries HALTAP and HALTAP01) in order to find a moiety with appropriate packing, ready for catenation between donor (I 3 − ) and acceptor (I 2 ) upon compression. Quaternary ammonium salts are often used as model cations for PI studies .…”

Section: Figurementioning

confidence: 99%

Pressure‐Induced Polymerization and Electrical Conductivity of a Polyiodide

Poręba

¹

,

Ernst

²

,

Zimmer

³

et al. 2019

View full text Add to dashboard Cite

We report the high-pressure structural characterization of an organic polyiodide salt in which ap rogressive addition of iodine to triiodide groups occurs.C ompression leads to the initial formation of discrete heptaiodide units, followed by polymerization to a3Danionic network. Although the structural changes appear to be continuous,t he insulating salt becomes as emiconducting polymer above1 0GPa.T he features of the pre-reactive state and the polymerized state are revealed by analysis of the computed electron and energy densities.T he unusually high electrical conductivity can be explained with the formation of new bonds.Polyiodides (PIs) in crystal form were discovered about 200 years ago. [1] Their structural diversity,which is due to the bonding flexibility of iodine,r emains the subject of continuous interest. [2][3][4] Nowadays,v arious PIs are known, ranging from I 3 À to I 29 3À ,with the general formula I nÀ 2 m+n and n up to 4. Their building blocks consist of I 3 À as adonor and I 2 as an acceptor forming ac harge transfer (CT) complex. CT complexes can interact further to form extended structures with various topologies,u pt oc ubic networks.A st he aggregation of iodine units is somewhat unpredictable,t he design of PIs is not easy.Moreover,the classification of higher units is,thus far,pragmatically based on the distance between iodine atoms,but universal criteria are still lacking.Different theoretical approaches to study bonds in PIs exist, for example,calculations of the potential energy surface and bond order, [5] energy decomposition analysis (EDA), [6] analysis of the electron density and its Laplacian at bond critical points (BCP), [7] theelectron localization function, and the one-electron potential. [8] Furthermore,t he energy den-

show abstract

The stable polyiodides: Experimental and theoretical studies of formation mechanism

Cited by 22 publications

References 26 publications

Pressure‐Induced Polymerization and Electrical Conductivity of a Polyiodide

Pressure‐Induced Polymerization and Electrical Conductivity of a Polyiodide

Triiodide Organic Salts: Photoelectrochemistry at the Border between Insulators and Semiconductors

Pressure‐Induced Polymerization and Electrical Conductivity of a Polyiodide

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