Donor Ligands Research Articles

A Multidimensional Approach to Carbodiphosphorane-Bismuth Coordination Chemistry: Cationization, Redox-Flexibility, and Stabilization of a Crystalline Bismuth Hydridoborate.

Bismuth complexes stabilized by carbon-based donor ligands are underserved by their instability, often due to facile ligand dissociation and deleterious protonolysis. Herein, we show that the ortho-bismuthination of hexaphenylcarbodiphosphorane enables a robust framework with geometrically constrained carbone-bismuth bonding interactions, which are highly tunable by cationization. The carbodiphosphorane bismuth halides (1 and 2) are remarkably air-stable and feature unprecedented trans carboneC-Bi-X ligation, resulting in highly elongated Bi-X bonds. In contrast to known carbone-bismuth complexes, hydrolytic activation of the carbone yields well-defined organobismuth complexes, and subsequent dehydrohalogenation is feasible using potassium bis(trimethylsilyl)amide or N-heterocyclic carbenes. The redox-flexibility of this framework was evaluated in the high catalytic activity of 1 and 2 for silylation of 2,2,6,6-tetramethylpiperidin-1-oxyl (TEMPO) under mild conditions (50 °C, 24-96 h) and low catalyst loadings (5-10 mol %), which suggests the accessibility of short-lived hydridic and radical bismuth species. The reaction of 1, PhSiH3, and tris(pentafluorophenyl)borane (BCF) yields the first crystallographically characterized bismuth hydridoborate complex as an ionic species (9), presumably by BCF-mediated hydride abstraction from an unobserved [Bi]-H intermediate. All isolated compounds have been characterized by heteronuclear NMR spectroscopy and X-ray crystallography, and the bonding situation in representative complexes (1, 2, 5, and 9) were further evaluated using density functional theory.

Combining a Low Valent Molybdenum(0) Center with a Strongly σ-Donating Mesoionic Carbene Chelate Ligand—Synthesis and Structural Characterization

Triazolylidene ligands belong to a class of N-heterocyclic carbenes of growing chemical interest. Their precursors are readily available using Click chemistry and, therefore, highly modular for tuning their electronic characteristics. Due to their notable donor properties, these ligands are particularly suitable for modulating the electronic properties of the central ions of their complexes. Here, a bidentate bistriazolylidene which is a particularly strong donor ligand is combined with a low valent molybdenum(0) center and four carbon monoxide molecules as co-ligands. The novel complex exhibits characteristic electrochemical and IR-spectroscopic behavior. An X-ray structural analysis provides metrical details which are not entirely in agreement with spectroscopic data, likely going back to crystal packing effects. In comparison with precursor and ligand SCXRD data, notable geometrical changes induced by the coordination of the ligand to the metal can be observed. The analyses strongly support the bistriazolylidene ligand as being a particularly good donor of electron density towards the central metal. Potentially, these findings may support, in the future, the design of potent catalysts for the reductive activation of small molecules.

A Series of Green Oxovanadium(IV) Precatalysts with O, N and S Donor Ligands in a Sustainable Olefins Oligomerization Process.

Designing catalyst systems based on transition metal ions and activators using the principles of green chemistry is a fundamental research goal of scientists due to the reduction of poisonous solvents, metal salts and organic ligands released into the environment. Urgent measures to reduce climate change are in line with the goals of sustainable development and the new restrictive laws ordained by the European Union. In this report, we attempted to use known oxovanadium(IV) green complex compounds with O, N and S donor ligands, i.e., [VO(TDA)phen] • 1.5 H2O (TDA = thiodiacetate), (phen = 1,10-phenanthroline), oxovanadium(IV) microclusters with 2-phenylpyridine (oxovanadium(IV) cage), [VOO(dipic)(2-phepyH)] • H2O (dipic = pyridine-2,6-dicarboxylate anion), (2-phepyH = 2-phenylpyridine), [VO(dipic)(dmbipy)] • 2H2O (dmbipy = 4,4'-dimethoxy-2,2'-dipyridyl) and [VO(ODA)(bipy)] • 2 H2O (ODA = oxydiacetate), (bipy = 2,2'-bipyridine), as precatalysts in oligomerization reactions of 3-buten-2-ol, 2-propen-1-ol, 2-chloro-2-propen-1-ol and 2,3-dibromo-2-propen-1-ol. The precatalysts, in most cases, turned out to be highly active because the catalytic activity exceeded 1000 g mmol-1·h-1. In addition, the oligomers were characterized by Fourier-transform infrared spectroscopy (FTIR), matrix-assisted laser desorption/ionization (MALDI-TOF-MS), thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC) techniques.

Oxo‐bridged Tri‐ and Tetra‐nuclear Cobalt Complexes Supported with Amide‐Based Nitrogen Donor Ligands

AbstractThis work presents two mixed‐valent μ3‐oxo‐bridged trinuclear [(Co2+)2Co3+] complexes 1 and 2 and a μ4‐oxo‐bridged tetranuclear [Co2+4] complex 3. Crystal structures of 1 and 2 showed the presence of triangular complexes having two Co2+ and one Co3+ centers bridged by a μ3‐oxo group. In contrast, complex 3 exhibited a tetrahedrally arranged μ4‐oxo‐bridged [Co2+4] core. A significant feature is the stabilization of unusual μ‐oxo‐bridged complexes exclusively supported with all nitrogen donor ligands. The X‐ray photoelectron spectroscopy confirmed the multiple oxidation states of cobalt ions in these complexes. Such oxo‐bridged cobalt complexes were investigated for their catalytic activity towards H2O2‐mediated oxidation of assorted benzyl alcohols.

Effects of chelate ligands containing NN, PN, and PP on the performance of half-sandwich ruthenium metal complexes as sensitizers in dye sensitized solar cells (DSSCs): Quantum chemical investigation

In this study, the structural and electronic properties of ruthenium dye derivatives of the type half sandwiches complexes presented to be utilized in dye-sensitized solar cells (DSSCs) as sensitizers were examined employing Density Functional Theory (DFT) and Time Dependent Density Functional Theory (TD-DFT) techniques. To design new ligands that raise dye performances in dye sensitized solar cells, O and N atoms in the donor ligand moiety were changed to S and P atoms respectively, in our substitution. Six dye derivatives Ru1(NO), Ru1(NS), Ru1(PS), Ru2(NO), Ru2(NS) and Ru2(PS) were theoretically built. Apart from the effect of ligand donor bonding modes on electronic properties, the impact of the lone pair of heteroatom N has also been investigated. The proposed dyes' absorption maxima have been studied. The substitution of (NO) bonding modes with (NS) or (PS) ones has a considerable impact on the electronic properties. Going from (NO) to (NS) or (PS), the intense absorption is shown in the absorption spectra of the suggested dyes. According to the photovoltaic characteristics of open circuit photovoltage (Voc), light harvesting efficiency (LHE), electron injection driving force (Ginj) and regeneration's free energy (Greg) the complexes Ru1(NS), Ru1(PS), and Ru2(PS) are showing promise in order to create novel dyes for solar cells.

Adsorption Behavior of Trivalent Actinides and Lanthanides on Tertiary Pyridine Resin in Sodium Nitrate Aqueous Solution

Investigation of absorption behavior of trivalent actinides (An(III)) and Trivalent lanthanides (Ln(III)) on tertiary pyridine resin in sodium nitrate (NaNO3) aqueous solution has been conducted. Am was used as trivalent actinides element and stable Europium (Eu) and Neodymium (Nd) represented Ln (III) elements. Separation of An (III) and Ln (III) was carried out by conducting chromatography experiment on pyridine resin column in high pH 11 of 4M NaNO3. High pH was adjusted in order to suppress the protonation and supports tertiary pyridine resin to work as N soft donor ligand during separation. Gamma spectrometry was performed for detection of 241Am and ICP-MS was used for measurement of Eu and Nd as stable isotopes.

Taming Heavier Group 14 Imine Analogues: Accessing Tin Nitrogen [Sn=N] Double Bonds and their Cycloaddition/Metathesis Chemistry

AbstractA systematic study to access stable stannaimines is reported, by combining different heteroleptic stannylenes with a range of organic azides. The reactions of terphenyl‐/hypersilyl‐substituted stannylenes yield the putative tin nitrogen double bond, but is directly followed by 1,2‐silyl migration to give SnIIsystems featuring bulky silylamido ligands. By contrast, the transition from a two σ donor ligand set to a mixed σ‐donor/π‐donor scaffold allows access to three new stannaimines which can be handled at room temperature. The reactivity profile of these Sn=N bonded species is crucially dependent on the substituent at the nitrogen atom. As such, the Sn=NMes (Mes=2,4,6‐Me3C6H2) system is capable of activating a broad range of substrates under ambient conditions via 1,2‐addition reactions, [2+2] and [4+2] cycloaddition reactions. Most interestingly, very rare examples of main group multiple bond metathesis reactions are also found to be viable.

Taming Heavier Group 14 Imine Analogues: Accessing Tin Nitrogen [Sn=N] Double Bonds and their Cycloaddition/Metathesis Chemistry.

A systematic study to access stable stannaimines is reported, by combining different heteroleptic stannylenes with a range of organic azides. The reactions of terphenyl-/hypersilyl-substituted stannylenes yield the putative tin nitrogen double bond, but is directly followed by 1,2-silyl migration to give SnII systems featuring bulky silylamido ligands. By contrast, the transition from a two σ donor ligand set to a mixed σ-donor/π-donor scaffold allows access to three new stannaimines which can be handled at room temperature. The reactivity profile of these Sn=N bonded species is crucially dependent on the substituent at the nitrogen atom. As such, the Sn=NMes (Mes=2,4,6-Me3 C6 H2 ) system is capable of activating a broad range of substrates under ambient conditions via 1,2-addition reactions, [2+2] and [4+2] cycloaddition reactions. Most interestingly, very rare examples of main group multiple bond metathesis reactions are also found to be viable.

Synthesis and Photophysical Studies of Copper(I) CAAC Half-Sandwich Complexes as a Highly Modifiable Class of Emitters.

Cyclopentadienyls are well-known strong donor ligands and have been successfully employed in catalysis as they tolerate a variety of substituents to adjust their steric and electronic properties. Although such highly modifiable ligands are of great interest for luminescence and photocatalytic applications, studies of CpR-containing photoactive transition-metal complexes are quite rare. In this work, we present a structural, electrochemical, and first elaborated photophysical investigation of a series of copper(I) half-sandwich complexes bearing cyclic alkyl(amino)carbenes (CAACs) as chromophore ligands and compare them with [Cu(Cp)(IDipp)] and [Cu(Cp*)(IDipp)] bearing a traditional N-heterocyclic carbene. Furthermore, we present the first molecular structure derived from single-crystal X-ray diffraction of a copper(I) indenyl complex, which can be described as an η2 (σ, π)-coordination. The CuI half-sandwich complexes show blue-green to orange phosphorescence with a photoluminescence quantum yield of up to 59% and radiative rate constants kr of up to 4 × 104 s-1 in the solid state, depending on the substitution pattern of the CpR ligand. Our TD/DFT calculations suggest that the emitting excited states are of 3MLCT/LLCT character. We determined the excited-state lifetime of the CuI half-sandwich complexes in solution to be as long as 600 ns, which in combination with the large π-surface of the CpR ligands allows for Dexter energy transfer for photocatalytic applications. In addition, the chiroptical properties of chiral [Cu(Cp/Cp*)(CAACMenthone)] were studied and compared to [CuCl(CAACMenthone)], of which we demonstrate that its circular polarized luminescence is the result of excimer formation and not, as previously reported, attributed to the monomeric C1-symmetric structure.

Synthesis and structural studies of quinolone-based Zn(II), Mn(II) and Ca(II) complexes involving supramolecular interactions

In the present work, we report a detailed investigation of four supramolecular coordination complexes, Zn(Quino)2(CH3OH)2 2, Zn(Quino)2H2O 3, Mn(Quino)2(CH3OH)2 4 and Ca(Quino)2(CH3OH)2 5, obtained from the self-assembling of Zn(II), Mn(II) and Ca(II) acceptors with the N-phenyl-4-hydroxyquinoline ligand donor QuinoH 1, possessing the β,β′-diketonate moiety. The structure of the supramolecular arrangement of the isolated complexes have been investigated by single crystal X-ray crystallography. The synthetic N-phenyl quinolone-linker that forms a π–π stacking supramolecular synthon with the coordination preferences of metal ions has been used to construct coordination driven self-assembled “metallosupramolecular” architectures.

Dinuclear PdII complexes bearing mixed NHC/Py/PPh3 donor set ligands: Catalytic applications and electrochemical investigations

Bimetallic palladium(II) complexes containing classical NHC donor ligands are becoming increasingly popular owing to their various catalytic applications. However, examples of the aforementioned complexes with mixed NHC/PPh3 ligands are still rare. Bimetallic palladium(II) complexes possessing these mixed ligands are described starting from a C2‐symmetric bis‐imidazolium salt containing 4,4′‐substituted central biphenyl ring. All the palladium(II) complexes have been tested as precatalysts in α‐arylation of oxindole and Suzuki–Miyaura coupling reactions. The complex composed of mixed NHC/PPh3 donor ligands shows superior catalytic activity compared with the corresponding PEPPSI type complexes when applied in α‐arylation of oxindole. The dinuclear complexes display better activity compared with the mononuclear complexes. The preliminary electrochemical measurements show the facile oxidation of PdII in the presence of combined NHC/PPh3 ligands compared with a combination of NHC/Py ligands.

Reactions of a Dioxidomolybdenum(VI) Complex with Thionation Reagents-Formation of Mo(IV) Species with Sulfur Donors.

Molecular molybdenum complexes with sulfur donor ligands are generally studied as soluble model compounds for molybdenum enzymes essential for life. The dioxidomolybdenum(VI) complex with tetradentate aminobisphenolate ligand undergoes a reaction with thionation reagent P2S5 or its organic derivative, Lawesson's reagent, to yield stable Mo(IV) aminobisphenolate complexes, where pristine oxido ligands have been replaced by bidentate sulfur donors tetrasulfide, S42- or (4-methoxyphenyl)phosphonotrithioate residue derived from Lawesson's reagent. This is in contrast to the behaviour of analogous dioxidotungsten(VI) complex, which, under similar conditions, yields W(VI) S2 systems. The overall cis,trans,cis geometry of the parent dioxidomolybdenum(VI) aminobisphenolate is retained, namely, the neutral nitrogen donors are in cis positions, phenolate oxygens are trans to each other and sulfur donors are cis. Although formally Mo(IV), thus d2 system, the studied complexes have diamagnetic singlet electron configurations as a result of the axially compressed octahedral structures.

Isolation and Purification of Actinides Using N,O-Hybrid Donor Ligands for Closing the Nuclear Fuel Cycle

Despite the fact that in the mass consciousness nuclear power is associated with increased environmental risks, this type of energy today remains one of the cleanest, most efficient and carbon neutral. Further development of nuclear energy is hampered by the problem of appropriate handling of spent nuclear fuel (SNF). A very attractive concept of the closed nuclear cycle has been developed to solve it. A real-life implementation of this concept requires the development of technological processes for the efficient separation of minor actinides from the rest of the SNF components. Recent progress in this area has been closely associated with N,O-hybrid donor ligands for liquid–liquid extraction. This work systematically reviews the available literature on the topic and provides detailed explanations on the behavior of the most perspective ligands. Notably, another important aspect of the application of N,O-hybrid donor ligands in nuclear cycle analytics through their incorporation in chemical sensors is also discussed.

Stability and bonding of carbon(0)-iron-N2 complexes relevant to nitrogenase co-factor: EDA-NOCV analyses.

The factors/structural features which are responsible for the binding, activation and reduction of N2 to NH3 by FeMoco of nitrogenase have not been completely understood well. Several relevant model complexes by Holland et al. and Peters et al. have been synthesized, characterized and studied by theoretical calculations. For a matter of fact, those complexes are much different than real active N2 -binding Fe-sites of FeMoco, which possesses a central C(4-) ion having an eight valence electrons as an μ6 -bridge. Here, a series of [(S3 C(0))Fe(II/I/0)-N2 ]n- complexes in different charged/spin states containing a coordinated σ- and π-donor C(0)-atom which possesses eight outer shell electrons [carbone, (Ph3 P)2 C(0); Ph3 P→C(0)←PPh3 ] and three S-donor sites (i.e. - S-Ar), have been studied by DFT, QTAIM, and EDA-NOCV calculations. The effect of the weak field ligand on Fe-centres and the subsequent N2 -binding has been studied by EDA-NOCV analysis. The role of the oxidation state of Fe and N2 -binding in different charged and spin states of the complex have been investigated by EDA-NOCV analyses. The intrinsic interaction energies of the Fe-N2 bond are in the range from -42/-35 to -67 kcal/mol in their corresponding ground states. The S3 C(0) donor set is argued here to be closer to the actual coordination environment of one of the six Fe-centres of nitrogenase. In comparison, the captivating model complexes reported by Holland et al. and Peter et al. possess a stronger π-acceptor C-ring (S2 Cring donor, π-C donor) and stronger donor set like CP3 (σ-C donor) ligands, respectively.

Evaluation of the crystal structures of metal(II) 2-fluorobenzoate complexes

Abstract When the structures of the complexes of the same primary ligand with different metals and different co-ligands are evaluated in detail, it is thought that it will be easier to reach the target molecules by determining the factors affecting the structure. The study of the structures of metal(II) 2-fluorobenzoates with various N-donor ligands is aimed to contribute to future research. In this study, the crystal structures of transition metal(II) 2-fluorobenzoates with N-donor ligand complexes such as 2,2′-bipyridine, 1,10′-phenanthroline, nicotinamide, isonicotinamide, 4-pyridylmethanol, and 2-aminopyridine were investigated. According to the literature review, it was determined that Cu(II), Zn(II), Cd(II), Pb(II), Co(II), and Ni(II) 2-fluorobenzoates with N-donor ligand exhibit monomeric, dimeric, ionic, and polymeric structures. Although the fluorobenzoate anion has the most electronegative element (fluorine) at the 2-position in the benzene ring, only a few of its complexes have O–H⋯F, N–H⋯F, and C–H⋯F hydrogen bonds. A Pb(II) 2-fluorobenzoate complex without an N- donor ligand is the only complex in which the fluorobenzoate anion coordinates to the metal via the fluorine atom. The structures of the 19 complexes studied included 11 monomers, 5 dimers, 2 ionic, and 1 coordination polymer. In addition, 8 of these complexes are copper(II), 5 of them are Pb(II), 2 of them are Cd(II) and Zn(II), and one of them is Co(II) and Ni(II) metal centered. Many transition metal(II) 2-fluorobenzoate complexes can still be contributed to the literature, according to the findings of this study. Furthermore, because metal carboxylate complexes have various physical and biological potential applications today, their importance in materials science should be emphasized.

Mimicking the Cu Active Site of Lytic Polysaccharide Monooxygenase Using Monoanionic Tridentate N-Donor Ligands.

In an effort to prepare small molecule mimics of the active site of lytic polysaccharide monooxygenase (LPMO), three monoanionic tridentate N donor ligands comprising a central deprotonated amide group flanked by two neutral donors were prepared, and their coordination chemistry with Cu(I) and Cu(II) was evaluated. With Cu(I), a dimer formed, which was characterized by X-ray crystallography and NMR spectroscopy. A variety of mononuclear and dinuclear Cu(II) species with a range of auxiliary ligands (MeCN, Cl–, OH–, OAc–, OBz–, CO32–) were prepared and characterized by X-ray diffraction and various spectroscopies (UV–vis, EPR). The complexes exhibit structural similarities to the LPMO active site.

Lanthanide Luminescence and Thermochromic Emission from Soft-Atom Donor Dichalcogenoimidodiphosphinate Ligands

The luminescence properties of two divalent europium complexes of the type Eu[N(SPPh2)2]2(THF)2 (1) and Eu[N(SePPh2)2]2(THF)2 (2) were investigated. The first complex, Eu[N(SPPh2)2]2(THF)2 (1), was found to be isomorphous with the reported structure of complex 2 and exhibited room temperature luminescence with thermochromic emission upon cooling. We found the complex Eu[N(SePPh2)2]2(THF)2 (2) was also thermochromic but the emission intensity was sensitive to temperature. Both room temperature and low temperature (100 K) single crystal X-ray structural investigation of 1 and 2 indicate geometric distortions of the metal coordination, which may be important for understanding the thermochromic behavior of these complexes. The trivalent europium complex Eu[N(SPPh2)2]3 (3) with the same ligand as 1 was also structurally characterized as a function of temperature and exhibited temperature-dependent luminescence intensity, with no observable emission at room temperature but intense luminescence at 77 K. Variable temperature Raman spectroscopy was used to determine the onset temperature of luminescence of Eu[N(SPPh2)2]3 (3), where the 615 nm (5D0 → 7F2 transition) peak was quenched above 130 K. The UV-visible diffuse reflectance of 3 provides evidence of an LMCT band, supporting a mechanism of thermally activated LMCT quenching of Eu(III) emitting states. A series of ten isomorphous, trivalent lanthanide complexes of type Ln[N(SPPh2)2]3 (Ln = Eu (3) Pr (4), Nd (5), Sm (6), Gd (7), Tb (8)) and Ln[N(SePPh2)2]3 (Ln = Pr (9), Nd (10, structure was previously reported), Sm (11), and Gd (12) for Q = Se) were also synthesized and structurally characterized. These complexes for Ln = Pr, Nd, Sm, and Tb exhibited room temperature luminescence. This study provides examples of temperature-dependent luminescence of both Eu2+ and Eu3+, and the use of soft-atom donor ligands to sensitize lanthanide luminescence in a range of trivalent lanthanides, spanning near IR and visible emitters.

Machine learning the frontier orbital energies of SubPc based triads.

Organic photovoltaic devices are promising candidates for efficient energy harvesting from sunlight. Designing new dye molecules suitable for such devices is a challenging task restricted by the rapid increase of computational cost with system size. Solar cell material properties are closely related to the electronic structure of the dye, and an effective molecular orbital energy screening method for a family of dyes is therefore desired. In this work, a machine learning approach is used to sort through the chemical space of peripheral double-substituted boron-Subphthalocyanine dyes. A database of 12,102 PM6 optimized structures was built and for each of the structures time-dependent density functional theory (LC-[Formula: see text]HPBE/6-31+G(d)) calculations were performed. We investigated the changes of the molecular orbital energies of the molecular orbitals related to reduction and oxidation of the compounds. With the Electrotopological-state index moleculear representation all the tested algorithms, Support Vector Machine, Random Forest Regression, Neural Network, and Simple Linear Regression, captured the calculated frontier orbital energies with a prediction root-mean-square-error in the order of 0.05 eV. Finally, frontier orbital energies were predicted for more than 40,000 new structures by the trained Support Vector Machine algorithm. Compared to the parent boron-Subphthalocyanine structure, 237 and 132 functionalized dyes were predicted to have upshifted molecular orbital energies using the Electrotopological-state index and OneHot encoding feature vector, respectively. Out of 27 investigated donor and acceptor ligands, the acetamide and hydroxyl ligands gave rise to the desired increase in frontier molecular orbital energy.

Ligand-stabilized heteronuclear diatomics of group 13 and 15.

A theoretical investigation of ligand-stabilized MX diatomics (M=group 13, X=group 15 element) with N-heterocyclic carbene (NHC) ligands has been carried out to assess bonding and electronic structure. Binding of two ligands in the form L-MX-L is generally preferred over binding of a single ligand as L-MX or MX-L. Binding of carbene donor ligands is predicted to be thermodynamically favorable for all the systems, and is very favorable for the lighter group 15 systems (nitrogen and phosphorus). Detailed analysis of the bonding in these complexes has been carried out with energy decomposition analysis (EDA). In all cases, the carbene to boron and carbene to nitrogen bonding is described as an electron-sharing double bond with both σ and π bonding interactions. For the heavier elements, bonding to C (except for PC interactions) is best described as a donor-acceptor σ single bond.

The effect of halogens in the coordination of 2-pyridinethioamide to gold centers

Primary thioamide, 2-pyridinethioamide reacts with gold compounds Na[AuCl4], [AuCl(tetrahydrothiophene)], AuBr3 and AuI to [AuCl2(2-pyridinecarboxamide)] (1), [AuCl(2-pyridinethioamide)]3 (2), [AuBr(2-pyridinethioamide)]3 (3), and [AuI(2-pyridinethioamide)] (4), respectively. Formation of 1 involves interconversion of thioamide to amide and creation of a N,Ń-auracycle. Compounds 2 and 3 both consist of linear trimeric adducts with aurophilic interactions between the gold atoms. In these compounds, the sulfur donor ligands show monodentate coordination. Similar monomeric unit is present in 4, which in solid state produces dimers via SS chalcogen interactions. The structures were determined by X-ray crystallography. Computational DFT calculations and topological charge density analysis were utilized to clarify interactions, which determine the structures in solid state.