Methylenverbindungen von Nichtmetallen. VI. Amide der Methan-bis(phosphonigsäure), -bis(phosphonsäure) und -bis(thiophosphonsäure)

Methylene Compounds of Non-Metals. VI. Amides of Methane-bis(phosphonous Acid), -bis(phosphonic Acid) and -bis(thiophosphonic Acid) Symmetrical- and asymmetrical-substituted amides of methane-bis(phosphonous acid), -bis(phosphonic acid) and -bis(thiophosphonic acid) have been obtained by stepwise aminolysis of the chlorides Cl₂(Z)PCH₂P(Z)Cl₂ ( 1 : Z = electron pair; 7 : Z = S; 13 : Z = O) and the fluoride F₂(S)PCH₂P(S)F₂ 19 with dimethylaminotrimethylsilane. Oxidation reactions of trivalent phosphonous amides with sulfur and dimethylsulfoxide have also been investigated.     

Synthese und Eigenschaften linearer Phosphorylchlorphosphazene

Synthesis and Properties of Lineary Phosphorylchlorphosphazenes The phosphorylchlorphosphazenes, Cl₂(O)P—[N?PCl₂]_n—Cl, (n = 1, 2, 3) react like POCl₃ with hexamethyldisilazan forming silylamides, Cl₂(O)P—[N ? PCl₂]_n—NHSi(CH₃)₃, (n = 0, 1, 2, 3). From these are obtained the phosphorylchlorphosphazenes by reaction with PCl₅ containing one group —N ? PCl₂ more.     

NH4[Re3Cl10(OH2)2] · 2 H2O: Synthese und Struktur Ein Beispiel für starke N?H …︁ O- und O?H …︁ Cl-Bindungen

NH₄[Re₃Cl₁₀(OH₂)₂] · 2 H₂O: Synthesis and Structure. An Example for “Strong” N? H …? O and O? H …? Cl Hydrogen Bonding The red NH₄[Re₃Cl₁₀(OH₂)₂] · 2 H₂O crystallizes from hydrochloric-acid solutions of ReCl₃ with NH₄Cl. It is tetragonal, P4₁2₁2, No. 92, a = 1157.6, c = 1614.5 pm, Z = 4. The crystal structure contains “isolated” clusters [Re₃Cl₁₀(OH₂)₂]^?. These contain Cl…?H? O? H…?Cl units with “very strong” hydrogen bonds: distances Cl? O are only 286 pm. NH₄⁺ has seven Cl^? as nearest neighbours and, additionally, one H₂O which belongs to a cluster [d(N? O1) = 271 pm] and one crystal water [d(N? O2) = 286 pm].     

Zweikernige Palladium(II)‐, Platin(II)‐ und Iridium(III)‐Komplexe von Bis[imidazol‐4‐yl]alkanen

Dinuclear Palladium(II), Platinum(II), and Iridium(III) Complexes of Bis[imidazol‐4‐yl]alkanes The reaction of bis(1,1′‐triphenylmethyl‐imidazol‐4‐yl) alkanes ((CH₂)_n bridged imidazoles L(CH₂)_nL, n = 3–6) with chloro bridged complexes [R₃P(Cl)M(μ‐Cl)M(Cl)PR₃] (M = Pd, Pt; R = Et, Pr, Bu) affords the dinuclear compounds [Cl₂(R₃P)M–L(CH₂)_nL–M(PR₃)Cl₂] 1 – 17 . The structures of [Cl₂(Et₃P)Pd–L(CH₂)₃L–Pd(PEt₃)Cl₂] ( 1 ), [Cl₂(Bu₃P)Pd–L(CH₂)₄L–Pd(PBu₃)Cl₂] ( 10 ), [Cl₂(Et₃P)Pd–L(CH₂)₅L–Pd(PEt₃)Cl₂] ( 3 ), [Cl₂(Et₃P)Pt–L(CH₂)₃L–Pt(PEt₃)Cl₂] ( 13 ) with trans Cl–M–Cl groups were determined by X‐ray diffraction. Similarly the complexes [Cl₂(Cp*)Ir–L(CH₂)_nL–Ir(Cp*)Cl₂] (n = 4–6) are obtained from [Cp*(Cl)Ir(μ‐Cl)₂Ir(Cl)Cp*] and the methylene bridged bis(imidazoles).     

Darstellung und Eigenschaften der Imidodiphosphorsäureamide

Preparation and Properties of Imidodiphosphoric Acid Amides Trichlorophosphazene phosphoryldichloride, Cl₃P?N? P(O)Cl₂, reacts with the stoichiometric amount of anhydrous formic acid resulting the tetrachloride of the imidodiphosphoric acid, Cl₂(O)P? NH? P(O)Cl₂. This tetrachloride yields with diazomethane the N-methyl compound, Cl₂(O)P? N(CH₃)? P(O)Cl₂. The tetramide of the imidodiphosphoric acid and its octalkyl derivatives are obtained by reaction of the tetrachloride with ammonia, dimethylamine, and diethylamine, respectively.     

A one‐dimensional ladder‐like six‐coordinate cadmium polymer: catena‐poly[bis[(S)‐2‐methylpiperazine‐1,4‐diium] [bis[trichloridocadmium(II)]‐di‐μ3‐chlorido]]

The crystal structure of the title compound {(C₅H₁₄N₂)₂[Cd₂Cl₈]}_n, (I), consists of hydrogen‐bonded 2‐methylpiperazinediium (H₂MPPA²⁺) cations in the presence of one‐dimensional polymeric {[CdCl₃(μ₃‐Cl)]²⁻}_n anions. The Cd^II centres are hexacoordinated by three terminal chlorides and three bridging chlorides and have a slightly distorted octahedral CdCl₃(μ₃‐Cl)₃ arrangement. The alternating CdCl₆ octahedra form four‐membered Cd₂Cl₂ rings by the sharing of neighbouring Cd–Cl edges to give rise to extended one‐dimensional ladder‐like chains parallel to the b axis, with a Cd...Cd distance of 4.094 (2) Å and a Cd...Cd...Cd angle of 91.264 (8)°. The H₂MPPA²⁺ cations crosslink the [CdCl₃(μ₃‐Cl)]_n chains by the formation of two N—H...Cl hydrogen bonds to each chain, giving rise to one‐dimensional ladder‐like H₂MPPA²⁺–Cl₂ hydrogen‐bonded chains [graph set R₄²(14)]. The [CdCl₃(μ₃‐Cl)]_n chains are interwoven with the H₂MPPA²⁺–Cl₂ hydrogen‐bonded chains, giving rise to a three‐dimensional supramolecular network.     

Bildung und NMR-spektroskopische Charakterisierung von Alk-(ar-)oxyderivaten von Trichlorphosphazen-N-phosphoryldichlorid,Cl3PN?P(O)Cl2, Imido- und N-Methylimidodiphosphoryltetrachlord,Cl2P(O)NHP(O)Cl2 bzw. Cl2P(O)N(CH3)P(O)Cl2

Formation and N.M.R.-Spectroscopic Characterization of Alk-(ar-)oxy Derivatives of Trichlorophosphazene-N-phosphoryldichloride, Cl₃P?N? P(O)Cl₂, Imido- and N-Methylimidodiphosphoryltetrachloride, Cl₂P(O)NHP(O)Cl₂ and Cl₂P(O)N(CH₃)P(O)Cl₂ The ester chlorides and esters P₂NOCl_5?x(OR)_x (x = 1?5), P₂(NH)O₂Cl_4?x(OR)_x (x = 1–4) and P₂(NCH₃)O₂Cl_4–x(OR)_x (x = 1–4) derived from the title compounds by substitution of chlorine atoms by alk- or aroxy groups are characterized by their ³¹P-n.m.r. data. The possibilities for forming these compounds by alcoholysis, chloridolysis, dealkylation and P? N-bond formation are discussed.     

Structural Characterization of trans-[Cr(NH3)4(H2O)Cl]Cl2 and trans-[Cr(NH3)4Cl2]l

Trans-[Cr(NH₃)₄(H₂O)Cl]Cl₂ (A) crystallizes in the monoclinic space group P2₁/m (No. 11) with a = 6.556(1), b = 10.630(5), c = 6.729(2) Å and β = 96.15(3)°. Trans-[Cr(NH₃)₄Cl₂]I (B) has monoclinic C2/m (No. 12) space group and a = 9.877(2), b = 8.497(2), c = 6.047(2) Å and β = 108.98(2)°. Both unit cells contain two formula units. Cr? Cl, Cr? O(H₂O) and three independent Cr? N(NH₃) distances for A are 2.98(1), 2.023(2), 2.067(2), 2.086(3) and 2.064(3) °. Cr? Cl and Cr? N(NH₃) bonds in B are 2.325(1) and 2.071(2) °. All octahedral angles are close to 90 and 180°. Both structures were refined to very low R values. Water molecule from trans-[Cr(NH₃)₄(H₂O)Cl]²⁺ is hydrogen bonded to both ionic chlorides. Cation and two anions form the motive which repeats itself in the crystal. Cations and anions of the second structure are distributed in layers. Each cation and anion have coordination number eight.     

Die Kristallstrukturen von [ReCl4(PhCCPh)]2 · 2 CH2Cl2 und von PPh4[ReOCl4]

Crystal Structures of [ReCl₄(PhC?CPh)]₂ · 2 CH₂Cl₂ and PPh₄[ReOCl₄] Single crystals of [ReCl₄(PhC?CPh)]₂ · 2 CH₂Cl₂ were obtained by chilling dilute solutions of the solvate [ReCl₄(PhC?CPh)POCl₃] in CH₂Cl₂. PPh₄[ReOCl₄] was formed by the reaction of the diphenyl acetylene complex [ReCl₅(PhC?CPh)] with PPh₄Cl · H₂O in CH₂Cl₂ solution. [ReCl₄(PhC?CPh)]₂ · 2 CH₂Cl₂: space group P2₁/c, Z = 2, 2244 observed independent reflexions, R = 0.038. Lattice parameters (19°C): a = 987.2 pm; b = 1533.9 pm; c = 1193.8 pm; β = 90.17° The compound forms centrosymmetrical dimeric molecules with ReCl₂Re bridges with Re? Cl distances of 241.2 and 267.6 pm. The longer Re? Cl bond is situated in trans-position to the equatorial, side-on coordinated diphenyl acetylene ligand with mean Re? C distances of 200 pm. PPh₄[ReOCl₄]: space group P4/n, Z = 2, 1487 observed, independent reflexions, R = 0.047. Lattice parameters (19°C): a = b = 1272.0 pm; c = 771.3 pm. The compound crystallizes in the AsPh₄[RuNCl₄] type; it consists of [ReOCl₄]^? anions and PPh₄⁺ cations. The anions are tetragonal with C_4v symmetry and bond lengths Re? O = 165.4 pm and Re? Cl = 232.6 pm; the bond angle OReCl is 106.7°.     

[La2Cl3(OAc)2(H2O)7]Cl: Das erste Lanthanid-Acetat-Halogenid-Hydrat mit Chlorid in innerer Koordinationssphäre

[La₂Cl₃(OAc)₂(H₂O)₇]Cl: The First Lanthanide-Acetate-Halide-Hydrate with Chloride in Inner-Sphere Coordination [La₂Cl₃(OAc)₂(H₂O)₇]Cl has been obtained as single crystals through the reaction of LaCl₃ · 7H₂O with diluted acetic acid or from La₂O₃ with acetyl chloride. In the crystal structure (triclinic, Z = 2, P1 (no. 2), a = 919.6(2), b = 950.7(2), c = 1178.9(2) pm, α = 82.52(1), β = 84.14(1), γ = 64.69(1)°, R = 0.021, R_w = 0.020), La³⁺ is surrounded by nine ligands (O, Cl). La1 has two chloride and seven oxygen ligands whereas La2 has one chloride and eight oxygen atoms as nearest neighbours. Four of the oxygen ligands of each lanthanum cation originate from a ?tetradentate”? acetate anion, the others from crystal water molecules. The ?tetradentate”? acetate groups are coordinated not only to one central La³⁺ as chelate ligands, but also to the ?left”? and ?right”? La³⁺ neighbours. Thereby, a one-dimensional infinite cationic chain, [La₂Cl₃(OAc)₂(H₂O)₇]⁺, is formed that runs in the [011] direction. These chains are held together by ?lonesome”? chloride ions which are surrounded by (4 + 1) water molecules and connected to the chains via hydrogen bonds.     

Synthese linearer und verzweigter Phosphazene aus N-silylierten Phosphorylamiden

Synthesis of Lineary and Branched Phosphazenes from N-silylated Phosphoryl Amides The use of N-silylated phosphoryl amides in the reaction with PCl₅ favours the KIRSANOV reaction and reduces undesirable substitution reactions. However, silylated monoamides, X₂P(O)NHSiMe₃ (X = OEt, NEt₂), do not give the expected trichlorophosphazenes but the isomeric N-dichlorophosphoryl phosphazenes, Cl₂P(O)? N?PClX₂, which are also formed in the reaction of (EtO)₂P(O)NCl₂ with PCl₅. As the first phosphoryl-P, P-bis(trichlorophosphazene) (EtO)P(O)(N?PCl₃)₂ could be obtained in the reaction of PCl₅ with the silylated diamide (EtO)P(O)(NHSiMe₃)₂. Tris reactivity of silylated amides to P? Cl compounds decreases in the row PCl₅ > POCl₃ > CIP(O)(OEt)₂ > ClP(O)(NEt₂)₂. In the reaction with phosphoryl chlorides the preferred formation of compounds with P? NH? P bridges could not be observed.     

Acetonyl­di­chloro­[(Z)‐2‐chloro‐2‐phenyl­vinyl]­tellurium(IV), helical chains of metal complexes

The primary geometry about the Te^IV atom in the title compound, [TeCl₂(C₈H₆Cl)(C₃H₅O)] or C₁₁H₁₁Cl₃OTe, is a pseudo‐trigonal‐bipyramidal arrangement, with two Cl atoms in apical positions, and the lone pair of electrons and C atoms in the equatorial plane. The Te^IV atom is involved in three secondary interactions, two intramolecular [Te?O = 2.842 (3) Å and Te?Cl3 = 3.209 (1) Å] and one intermolecular [Te?Cl = 3.637 (1) Å], the latter giving rise to a helical chain. These helices are linked by C—H?O interchain interactions.     

Preparation and properties of perfluorochloromethyl-mercaptophosphoryldichlorides and -chlorophosphanes

In Arbuzov-type reactions CF_nCl_3?nSCl reacts with ROPCl₂ (R = CH₃, C₂H₅) to give CF_nCl_3?nSP(O)Cl₂ (n = 3,2,1,0). The corresponding reaction with CF₃SeX (X = Cl, Br) produces CF₃SeP(O)Cl₂ in good yields only in the presence of catalysts such as SbCl₅ or BCl₃. Reactions between P₄ and the sulfenylchlorides produce (CF_nCl_3?nS)_xPCl_3?n (n = 3,2,1 and x = 1,2). On heating CF_n′ Cl_3?n′ SP(O)Cl₂ (n′ = 2,1,0) decompose to P(O)Cl₃ and SCF_n′ Cl_2?n′. During this process fluorination of P(O)Cl₃ to P(O)F₃ by SCF₂ is observed. A Cl/Br exchange between CF_nCl_3?nSP(O)Cl₂ (n = 3,2) and PBr₃ was proved ¹⁹F? and ³¹P-NMR-spectroscopically.Chemical and physical properties of the newly synthesized compounds will be discussed.     

Synthesis,Structure and Photoluminescent Properties of Zn(II)/Cd(II)‐Complexes Containing 2,4,6‐Tris‐(benzimidazolyl‐2‐yl)pyridine Ligand

Hydrothermal reactions of tridentate rigid 2,4,6‐tris‐(benzimidazolyl‐2‐yl)pyridine (pytbzim) ligand and Zn(II)/Cd(II) salts generate binuclear complexes {[Cd₂Cl₂(pytbzim)₂(H₂O)₂]·2NO₃}_n ( 1 ) and two isomorphs {[M₂Cl₂(pytbzim)₂(H₂O)₂]Cl₂·2H₂O}_n [M=Cd ( 2 ), Zn ( 3 )]. All complexes include [M₂Cl₂(pytbzim)₂(H₂O)₂] dimers, which are further connected into a three‐dimensional supramolecular networks through ?‐? stacking interaction and hydrogen bonds. The solid state photoluminescent studies reveal good fluorescent properties of the pytbzim ligand and complexes 1 – 2 at room temperature.     

Dichlorphosphatokomplexe der Nitridchloride von Molybdän und Wolfram

Dichlorophosphate Complexes of the Nitrido Chlorides of Molybdenum and Tungsten Tetraphenylarsonium dichlorophosphate AsPh₄[PO₂Cl₂], is prepared by the reaction of AsPh₄Cl with P₂O₃Cl₄. The vibrational spectrum is reported as well as the valence force constants of the [PO₂Cl₂]^? ion. The f-values are clearly smaller than those of the isoelectronic SO₂Cl₂ molecule. The dichlorophosphate ion forms complexes with the nitride chlorides MNCl₃ (M ? Mo, W) of the type [MNCl₃(PO₂Cl₂)]₂^2?, which are characterized by their i.r. spectra.     

3‐Rhoda‐1,2‐diazacyclopentanes: A Series of Novel Metallacycle Complexes Derived From CN Functionalization of Ethylene

Rh‐containing metallacycles, [(TPA)Rh^III(κ²‐(C,N)‐CH₂CH₂(NR)₂‐]Cl; TPA=N,N,N,N‐tris(2‐pyridylmethyl)amine have been accessed through treatment of the Rh^I ethylene complex, [(TPA)Rh(η²‐CH₂CH₂)]Cl ([ 1 ]Cl) with substituted diazenes. We show this methodology to be tolerant of electron‐deficient azo compounds including azo diesters (RCO₂N?NCO₂R; R=Et [ 3 ]Cl, R=iPr [ 4 ]Cl, R=tBu [ 5 ]Cl, and R=Bn [ 6 ]Cl) and a cyclic azo diamide: 4‐phenyl‐1,2,4‐triazole‐3,5‐dione (PTAD), [ 7 ]Cl. The latter complex features two ortho‐fused ring systems and constitutes the first 3‐rhoda‐1,2‐diazabicyclo[3.3.0]octane. Preliminary evidence suggests that these complexes result from N–N coordination followed by insertion of ethylene into a [Rh]?N bond. In terms of reactivity, [ 3 ]Cl and [ 4 ]Cl successfully undergo ring‐opening using p‐toluenesulfonic acid, affording the Rh chlorides, [(TPA)Rh^III(Cl)(κ¹‐(C)‐CH₂CH₂(NCO₂R)(NHCO₂R)]OTs; [ 13 ]OTs and [ 14 ]OTs. Deprotection of [ 5 ]Cl using trifluoroacetic acid was also found to give an ethyl substituted, end‐on coordinated diazene [(TPA)Rh^III(κ²‐(C,N)‐CH₂CH₂(NH)₂‐]⁺ [ 16 ]Cl, a hitherto unreported motif. Treatment of [ 16 ]Cl with acetyl chloride resulted in the bisacetylated adduct [(TPA)Rh^III(κ²‐(C,N)‐CH₂CH₂(NAc)₂‐]⁺, [ 17 ]Cl. Treatment of [ 1 ]Cl with AcN?NAc did not give the Rh?N insertion product, but instead the N,O‐chelated complex [(TPA)Rh^I ( κ²‐(O,N)‐CH₃(CO)(NH)(N?C(CH₃)(OCH?CH₂))]Cl [ 23 ]Cl, presumably through insertion of ethylene into a [Rh]?O bond.     

Cl/Cl isotope effects in Rh NMR of [RhCln(H2O)6−n] complex anions in hydrochloric acid solution as a unique ‘NMR finger-print’ for unambiguous speciation

A detailed analysis of the ³⁵Cl/³⁷Cl isotope effects observed in the 19.11 MHz ¹⁰³Rh NMR resonances of [RhCl_n(H₂O)_6−n]³⁻ⁿ complexes (n = 3–6) in acidic solution at 292.1 K, shows that the ‘fine structure’ of each ¹⁰³Rh resonance can be understood in terms of the unique isotopologue and in certain instances the isotopomer distribution in each complex. These ³⁵Cl/³⁷Cl isotope effects in the ¹⁰³Rh NMR resonance of the [Rh^35/37Cl₆]³⁻ species manifest only as a result of the statistically expected ³⁵Cl/³⁷Cl isotopologues, whereas for the aquated species such as for example [Rh^35/37Cl₅(H₂O)]²⁻, cis-[Rh^35/37Cl₄(H₂O)₂]⁻ as well as the mer-[Rh^35/37Cl₃(H₂O)₃] complexes, additional fine-structure due to the various possible isotopomers within each class of isotopologues, is visible. Of interest is the possibility of the direct identification of stereoisomers cis-[RhCl₄(H₂O)₂]⁻, trans-[RhCl₄(H₂O)₂]⁻, fac-[RhCl₃(H₂O)₃] and mer-[RhCl₃(H₂O)₃] based on the ¹⁰³Rh NMR line shape, other than on the basis of their very similar δ(¹⁰³Rh) chemical shift. The ¹⁰³Rh NMR resonance structure thus serves as a novel and unique ‘NMR-fingerprint’ leading to the unambiguous assignment of [RhCl_n(H₂O)_6−n]³⁻ⁿ complexes (n = 3–6), without reliance on accurate δ(¹⁰³Rh) chemical shifts.     

Synthese von Nitrenkomplexen mit N-Trimethylsilylanilin. II. Charakterisierung und Kristallstruktur der Rhenium(V)-phenylnitren-Komplexe mer-[Re(NPh)Cl3(NH2Ph)(Ph3P)] und trans-[Re(NPh)(OMe)Cl2(Ph3P)2]

Synthesis of Phenylnitrene Complexes with N-Trimethylsilylaniline. II. Characterization and Crystal Structure of the Rhenium(V) Complexes mer-[Re(NPh)Cl₃(NH₂Ph)(Ph₃P)] and trans-[Re(NPh)(OMe)Cl₂(Ph₃P)₂] Reaction of [ReOCl₃(Ph₃P)₂] with N-trimethylsilylaniline yields mer-[Re(NPh)Cl₃(Ph₃P)₂], which reacts under air with excess of N-trimethylsilylaniline to form [Re(NPh)Cl₃ · (NH₂Ph)(Ph₃P)]. Crystallization from CH₂Cl₂/MeOH affords [Re(NPh)(OMe)Cl₂(Ph₃P)₂] as an additional product. [Re(NPh)Cl₃(NH₂Ph)(Ph₃P)] crystallizes in the monoclinic space group P2₁/n with a = 1 192.3(3); b = 1 918.9(3); c = 1 266.3(3) pm; β = 101.71(1)°; Z = 4. The rhenium atom has a distorted octahedral environment with the Cl atoms in meridional positions. The phenyl nitrene ligand is coordinated with an almost linear arrangement Re? N1? C40 = 166.8(6)° and with a bond distance Re?N = 170.5(6) pm. [Re(NPh)(OMe)Cl₂(Ph₃P)₂] · 1/2CH₂Cl₂ crystallizes in the triclinic space group P1 : a = 1 103.1(4); b = 1 227.9(4); c = 1 711.3(5) pm; α = 70.48(3)°; β = 72.71(3)°; γ = 80.03(3)°; Z = 2. The rhenium atom exhibits a distorted octahedral coordination with the Cl atoms and the phosphine ligands in trans positions. As a consequence of the competition of the nitrene ligand and the trans-coordinated methoxy group the Re?;N bond length is slightly lengthened to 173.2(7) pm, while the Re? O bond length of 193.4(6) pm is short. The bond angles Re? N? C70 and Re? O? C80 are 173.3(7)° and 139.1(7)°, respectively.     

catena‐Poly[1,4‐dihydroxy‐1,4‐diazoniabicyclo[2.2.2]octane [aquatri‐μ‐chlorido‐trichloridodicuprate(II)]]

The title compound, {(C₆H₁₄N₂O₂)[Cu₂Cl₆(H₂O)]}_n, consists of 1,4‐dihydroxy‐1,4‐diazoniabicyclo[2.2.2]octane dications and one‐dimensional inorganic anionic {[Cu₂Cl₆(H₂O)]²⁻}_n chains in which both five‐coordinate [CuCl₃(H₂O)]⁻ and five‐coordinate [CuCl₃]⁻ units exist. These two distinct type of unit are linked together by one chloride ion and are bridged across centres of inversion to further units of their own type through two chloride ions, giving rise to novel polymeric zigzag chains parallel to the c axis. The chains are connected by O—H...Cl hydrogen bonds to produce R₂⁴(16) ring motifs, resulting in two‐dimensional layers parallel to the ac plane. These layers are linked into a three‐dimensional framework with the organic cations via O—H...Cl hydrogen bonds. Hydrogen bonding between the chains, and between the chains and the organic cations, provides stability to the crystal structure.     

Photophysical Processes in ‘Supramolecular Balls’ Formed by Lanthanide Chloride with 2,2′‐Bipyridine

The europium complex [EuCl₂(bpy)₂(H₂O)₂]Cl?1.25 C₂H₆O?0.37 H₂O, where bpy is 2,2′‐bipyridine, was synthesized and investigated with the aim to relate its molecular geometry and crystal packing to the efficiency of energy‐transfer processes. The presence of H‐bonds between noncoordinated Cl^? ions and coordinated H₂O molecules leads to the formation of discrete trimers assembled by a number of C? H???Cl and stacking interactions into ‘supramolecular balls’ which contain Cl^? ions and solvate molecules (H₂O and EtOH). The additional stabilization of the complex is due to intramolecular N???C interactions between two bpy ligands that causes some shortening of the Eu? N bonds. Deciphering the luminescence properties of the Eu complex was performed under consideration of both the composition of the inner coordination sphere and the peculiarities of the crystal packing. The influence of the latter and the bpy orientation on the energy of the ligand→Eu charge‐transfer state (LMCT) was established, and an additional excited state induced by the π‐stacking interaction (SICT) was identified.