Copper and silver heterometallic iodoantimonates: structure, thermal stability, and optical properties.

Seven heterometallic iodoantimonates with the general formula (Cat)2{[Sb2M2I10]} (M = Cu(I) (1-6), Ag(I) (7)) were prepared. X-ray diffraction data indicate that these compounds are the first Sb(III) representatives of the structural type previously known only for heterometallic iodobismuthates(III). In 3 and 4, halogen-substituted cations form halogen bonds with the heterometallic halometalate chain. 1-7 show prominent thermal stability. The estimated optical band gaps lie between 2.16 and 2.40 eV. As in heterometallic iodobismuthates, incorporation of Cu+ rather than Ag+ provides a much lower band gap.

Copper- and Silver-Containing Heterometallic Iodobismuthates: Features of Thermochromic Behavior.

Nine heterometallic iodobismuthates with the general formula Cat2{[Bi2M2I10}] (M = Cu(I), Ag(I), Cat = organic cation) were synthesized. According to X-ray diffraction data, their crystal structures consisted of {Bi2I10} units interconnected with Cu(I) or Ag(I) atoms through I-bridging ligands, forming one-dimensional polymers. The compounds are thermally stable up to 200 °C. Optical band gaps (Eg), estimated at room temperature via diffuse reflectance measurements, range from 1.81 to 2.03 eV. Thermally induced changes in optical behavior (thermochromism) for compounds 1-9 were recorded, and general correlations were established. The thermal dependence of Eg appears to be close to linear for all studied compounds.

Bismuth and antimony halometalates containing photoswitchable ruthenium nitrosyl complexes.

The first examples of Bi(III) and Sb(III) halide compounds combined with a photoswitchable ruthenium nitrosyl unit are reported. The structures of [RuNOPy4Br]4[Sb2Br8][Sb3Br12]2 (1) and (H3O)[RuNOPy4Br]4[Bi2Br9]3·3H2O (2) were determined by X-ray diffraction, and exhibit three different structural types of group 15 halometalates. Low-temperature IR-spectroscopy measurements reveal that the irradiation of 1 at 365 nm switches a stable Ru-NO (GS) unit to a metastable Ru-ON (MS1) linkage. Moreover, the light excitation of 2 at 365 or 405 nm induces the additional formation of a side-bond isomer Ru-η2-(NO) (MS2). The reverse reactions MS1/MS2 → GS can be induced by red-infrared light irradiation or by heating at temperatures >200 K. The obtained synthetic and spectroscopic data open the way for the preparation of hybrid halide complexes with a variety of photoswitchable complexes (NO2, SO2, N2, etc.), and give an insight into the behavior of light-induced species embedded in polynuclear halides.

One-Dimensional Iodoantimonate(III) and Iodobismuthate(III) Supramolecular Hybrids with Diiodine: Structural Features, Stability and Optical Properties.

Two isostructural pairs of supramolecular iodoantimonate(III) and iodobismuthate(III) complexes with I2 units "trapped" in solid state via halogen bonding-Cat3[[M2I9](I2)} (Cat = tetramethylammonium and 1-methylpyridinium, M = Sb(III) and Bi(III)) were prepared. For all compounds, values of optical band gaps were determined, together with thermal stability; the complexes were additionally characterized by Raman spectroscopy.

Selenium(IV) Polybromide Complexes: Structural Diversity Driven by Halogen and Chalcogen Bonding.

Reactions between bromoselenate(IV)-containing solutions, dibromine and salts of pyridinium-family organic cations resulted in structurally diverse, bromine-rich polybromine-bromoselenates(IV): (4-MePyH)5[Se2Br9][SeBr6](Br3)2 (1), (2-MePyH)2{[SeBr6](Br2)} (2), (PyH)2{[SeBr5]Br(Br2)2} (3), (1-MePy)2{[SeBr6](Br2)} (4). The compounds feature halogen and (in the case of 3) chalcogen bonding in solid state, resulting in formation of supramolecular architectures of different dimensionality. DFT calculations allowed estimation of the energies of non-covalent interactions in 1-4; additionally, characterization by Raman spectroscopy was performed.

Supramolecular Diiodine-Bromostannate(IV) Complexes: Narrow Bandgap Semiconductors.

Three supramolecular bromostannates(IV) with "trapped" diiodine molecules, Cat2{[SnBr6](I2)} (Cat = Me4N+ (1), 1-MePy+ (2) and 4-MePyH (3)), were synthesized. In all cases, I2 linkers are connected with bromide ligands via halogen···halogen non-covalent interactions. Articles 1-3 were studied using Raman spectroscopy, thermogravimetric analysis, and diffuse reflectance spectroscopy. The latter indicates that 1-3 are narrow band gap semiconductors.

Zn(II) and Co(II) 3D Coordination Polymers Based on 2-Iodoterephtalic Acid and 1,2-bis(4-pyridyl)ethane: Structures and Sorption Properties.

Metal-organic frameworks [M2(2-I-bdc)2bpe] (M = Zn(II) (1), Co(II) (2), 2-I-bdc = 2-iodoterephtalic acid, and bpe = 1,2-bis(4-pyridyl)ethane) were prepared and characterized by X-ray diffractometry. Both compounds retain their 3D structure after the removal of guest DMF molecules. Selectivity of sorption of different organic substrates from the gas phase was investigated for both complexes.

Zn(II) Heteroleptic Halide Complexes with 2-Halopyridines: Features of Halogen Bonding in Solid State.

Reactions between Zn(II) dihalides and 2-halogen-substituted pyridines 2-XPy result in a series of heteroleptic molecular complexes [(2-XPy)2ZnY2] (Y = Cl, X = Cl (1), Br (2), I (3); Y = Br, X = Cl (4), Br (5), I (6), Y = I, X = Cl (7), Br (8), and I (9)). Moreover, 1-7 are isostructural (triclinic), while 8 and 9 are monoclinic. In all cases, halogen bonding plays an important role in formation of crystal packing. Moreover, 1-9 demonstrate luminescence in asolid state; for the best emitting complexes, quantum yield (QY) exceeds 21%.

Oxochloroselenate(IV) with Incorporated {Cl2 }: The Case of Strong Cl⋠⋠⋠Cl Halogen Bonding.

Reaction of SeO2 , tetramethylammonium (TMA) chloride, aqueous HCl and Cl2 yields oxochloroselenate with incorporated Cl2 units, TMA3 {[Se2 O2 Cl7 ](Cl2 )}. The main feature of this compound is the strong (up to 3.5 kcal mol-1 , according to DFT calculations) Cl⋅⋅⋅Cl bonding, which is also detected by Raman spectroscopy.

Rule, Not Exclusion: Formation of Dichlorine-Containing Supramolecular Complexes with Chlorometalates(IV).

Supramolecular derivatives of chlorostannate(IV) and -plumbate(IV) with {Cl2} units, Cat2{[MCl6](Cl2)x} (1-5; M = Sn, Pb, cat = 1-methylpyridinium (1-MePy), tetramethylammonium (TMA)) were prepared and characterized by X-ray diffractometry and Raman spectroscopy. In particular, the TMA-containing complexes demonstrate remarkable thermal stability, releasing Cl2 only at elevated temperatures.

Unexpected Polymorphism in Bromoantimonate(III) Complexes and Its Effect on Optical Properties.

Reactions of [SbBr6]3- containing HBr solutions with bromide salts of 1,1'-(1,2-ethanediyl)bis(pyridine) (PyC22+) or 1,1'-(1,2-ethanediyl)bis(3,5-dimethylpyridine) (3,5-MePyC22+) initially result in the formation of the deep orange complexes Cat[SbBr5] (1 and 2), featuring unusual Sb···Br interactions in the solid state. In the mother liquor, 1 transforms into discrete binuclear (C2Py)2[Sb2Br10], which demonstrates polymorphism (triclinic 3 and monoclinic 4), while 2 transforms into polymeric (3,5-MePy){[SbBr4]} (5). DFT calculations reveal that the system of noncovalent Sb···Br contacts may be responsible for the appearance of the observed optical properties (unusual deep orange coloring).

One-Dimensional Diiodine-Iodobismuthate(III) Hybrids Cat3{[Bi2I9](I2)3}: Syntheses, Stability, and Optical Properties.

One-dimensional iodine-rich iodobismuthates(III), Cat3{[Bi2I9](I2)3} [Cat = 1,4-MePy (1) and 1-EtBMAP (2)], feature the highest amount of "trapped" diiodine units in polyhalogen-halometalates of p-block elements. Both complexes have narrow optical band gaps (1.55 and 1.63 eV, respectively) and moderate thermal stability.

Memory devices based on novel alkyl viologen halobismuthate(iii) complexes.

Four novel halobismuthate(iii) complexes with alkyl viologen cations: (R2Viol)2[Bi2X10] (R = n-butyl, n-pentyl, X = Cl, Br) have been synthesized. Both chloride complexes revealed photochromic behavior and were successfully utilized for the fabrication of OFET-based memory devices with high switching coefficients and good write-read-erase cycling stability.

Opening the Third Century of Polyhalide Chemistry: Thermally Stable Complex with "Trapped" Dichlorine.

Unlike polyhalides of heavier halogens, polychlorides still remain exotic curiosities. Herein, we report preparation and investigation of complexes Cat2 {[TeCl6 ](Cl2 )} (cat=1-methylpyridinium (1) and tetramethylammonium (2)) where dichlorine units are "trapped" by chlorotellurate(IV) anions via a system of non-covalent Cl⋅⋅⋅Cl interactions. Complex 2 reveals a record thermal stability (>100 °C) for inclusion compounds with Cl2 , indications that such compounds can be used as solid Cl2 source.

One- and Two-Dimensional Iodine-Rich Iodobismuthate(III) Complexes: Structure, Optical Properties, and Features of Halogen Bonding in the Solid State.

Reactions of BiI3, I2, and iodide salts of two different pyridinum cations result in the formation of the novel iodine-rich iodobismuthates(III) (1,3-MePy)4{[Bi4I16](I2)} (1) and (1-MePy){[BiI4](I2)0.5) (2), where the halometalate anions are connected by diiodine linkers into one- or two-dimensional supramolecular structures. Both complexes reveal narrow optical band gaps and fairly high thermal stability, favoring their potential use in photovoltaic devices.

A Novel Family of Polyiodo-Bromoantimonate(III) Complexes: Cation-Driven Self-Assembly of Photoconductive Metal-Polyhalide Frameworks.

In the presence of different cations, reactions of [SbBr6 ]3- and I2 result in a new family of diverse supramolecular 1D polyiodide-bromoantimonate networks. The coordination number of Sb, as well as geometry of assembling {Ix }n- polyhalide units, can vary, resulting in unprecedented structural types. The nature of I⋅⋅⋅Br interactions was studied by DFT calculations; estimated energy values are 1.6-6.9 kcal mol-1 . Some of the compounds showed strong photoconductivity in thin films, suggesting multiple feasible applications in optoelectronics and solar energy conversion.

Bromo- and Polybromoantimonates(V): Structural and Theoretical Studies of Hybrid Halogen-Rich Halometalate Frameworks.

Cation-dependent reactions "[SbBr6 ]3- +Br2 +HBr+CationBrx " result in the formation of bromide/polybromide complexes with zero-, one-, two-, or three-dimensional supramolecular frameworks and different Br/Sb ratios (up to 11). Seven new compounds representing six structural types were characterized by XRD and thermogravimetric analysis and DFT calculations enabled estimation of the energies of the Br⋅⋅⋅Br contacts (1.1-4.6 kcal mol-1 ).

Bromine-rich complexes of bismuth: experimental and theoretical studies.

Three novel polybromide complexes of bismuth(iii) - (2,6-MePyH)3[BiBr5(Br3)] (1), (H2bpp){[BiBr5](Br2)} (2) and (3-ClPyH)2{[BiBr5](Br2)} (3) - were synthesized. The results of an extended screening involving a set of organic cations resulting in the formation/non-formation of Bi(iii) polybromides are presented and discussed. The nature of BrBr interactions in Bi(iii) polybromides was investigated by theoretical methods, enabling the estimation of their energies.

Halogen Contacts-Induced Unusual Coloring in BiIII Bromide Complex: Anion-to-Cation Charge Transfer via Br⋠⋠⋠Br Interactions.

A yellow bromobismuthate {(2-BrPy)2 H}[BiBr4 ] (1, 2-BrPy=2-bromopyridinium) transforms into the unusually deeply colored cherry-red (2-BrPyH)2 [BiBr5 ] (2). A combination of structural studies and theoretical calculations confirms that the appearance of short non-covalent Br⋅⋅⋅Br interactions (≈3.3 Å) in 2 is responsible for the anion-to-cation charge transfer (LP(Brligand )→σ*(Br-C)), yielding dramatic changes in optical behavior. This effect opens the way towards novel halogen bonding-templated halometalate-based hybrid materials with enhanced optical properties.

Bi(iii) polybromides: a new chapter in coordination chemistry of bismuth.

A new family of bismuth coordination compounds - Bi(iii) polybromides - is introduced. Four representatives of this class - (N-EtPy)3[Bi2Br9](Br2)2 (1), (4-MePyH)3[Bi2Br9](Br2) (2), (H2bpe){[BiBr5]}(Br2) (3) and (BPB)2[BiBr5(Br3)](Br3)(Br2) (4) - were obtained in a simple way from HBr solutions of BiBr3 with added Br2, highlighting the diversity of the structural types in the new family of complexes.