Metal dimers as catalysts: IX. The catalysed reaction between [η5-C5H5)Fe(CO)2I] and group 15 donor ligands

The reaction between [η⁵-C₅H₅)Fe(CO)₂I] (I) and 1 equivalent of L (group 15 donor ligand) in the presence of catalysts (e.g. Pd/CaCO₃, PdO, [η⁵-C₅H₅)Fe(CO)₂]₂ (II)) yields [η⁵-C₅H₅)Fe(CO)(L)I] (phosphines, diphosphines, phosphite), [η⁵-C₅H₅)Fe(CO)₂L]I (phosphines) and [η⁵-C₅H₅)Fe(CO)(LL)]I (diphosphines). [η⁵-C₅H₅)Fe(CO)₂L]I can be converted into [η⁵-C₅H₅)Fe(CO)(L)I] in the presence of II. The reaction between [η⁵-C₅H₅)Fe(CO)(PMePh₂)I] or [η⁵-C₅H₅)Fe(CO)₂(PMePh₂)]I and PMePh₂ is also catalysed by II and yields in both instances [η⁵-C₅H₅)Fe(CO)(PMePh₂)₂]I. In the series of catalysed reactions the displacement sequence was found to be PMePh₂ > I⁻ > CO.     

Reactivity of linked metal units: The thermal decomposition of derivatives of iron containing multiple alkylmetal groups

The results of thermal decomposition studies of derivatives of iron containing multiple alkylmetal groups (CH₃)₂Si[η⁵-C₅H₄Fe(CO)₂C₅H₁₁]₂ (I), {(CH₃)₂Si[η⁵-C₅H₄Fe(CO)₂]₂(CH₂)₅}₂ (II) and [η⁵-C₅H₅Fe(CO)₂]₂ (CH₂)₅ (III) are presented and compared with the results obtained for η⁵-C₅H₅Fe(CO)₂C₅H₁₁ (IV). Compounds II and III are found to produce principally 1-pentene and therefore do not decompose principally by a β-hydrogen elimination steps. Compound I decomposes principally by a β-hydrogen elimination process but produces significantly more pentane in its reactions than does IV.     

Mixed halodicyclopentadienyl-niobium(V) and -tantalum(V)

Oxidation of (η⁵-C₅H₅)₂MCl (M = Nb, Ta) with 1 mol of Cl₂, Br₂ or I₂ gives (η⁵-C₅H₅)₂MClX₂ whereas the reaction with an excess of the halogen gives the cationic complexes [η⁵-C₅H₅)₂MClX]⁺ X₃^? (X = Br, I). Similar oxidation of (η⁵-C₅H₅)₂MCl₂ with 0.5 mol of halogen gives (η⁵-C₅H₅)₂MCl₂X complexes, but if the halogen is used in excess cationic [η⁵-C₅H₅)₂MCl₂]⁺ X₃^? (X = Br, I; M = Ta and X = I, M = Nb) are obtained. All these complexes can also be obtained simultaneously by oxidizing (η⁵-C₅H₅)₄M₂Cl₃, and the separation is fairly easy in most cases. Conductivity and IR and NMR data are discussed.     

Mechanism of the thermal decomposition of (η5-C5H5)Fe(CO)2(η1-acenaphthenyl)

The complexes (η⁵-C₅H₅)Fe(CO)₂(η¹-acenaphthenyl) (I), (η⁵-C₅H₅)Fe(CO)₂ (η¹-trans-β-deuterioacenaphthenyl) (II), and (η-C₅D₅)Fe(CO)₂, (η¹-acenaphthenyl) (XIII) have been prepared and their thermal decomposition studied in vacuo and in refluxing toluene. All three complexes decompose to produce mixtures of acenaphthene (VII), acenaphthylene (VIII), and [C₅H₅Fe(CO)₂]₂ (VI). Biacenaphthenyl (IX) is also obtained from the thermolysis of I in toluene. The formation of alkene VIII, and, to a lesser extent, alkane VII is suppressed by external CO. Thermolysis of I in toluene-d₈ and of II in vacuo and in toluene produces deuterium-enriched VII. The acenaphthene generated from the decomposition of XIII also contains deuterium. The above observations are accomodated by a mechanistic scheme involving competing β-elimination, ironcarbon bond homolysis to produce the acenaphthenyl radical, and CpH abstraction by an undetermined pathway.     

Multikern-NMR-untersuchung eines paramagnetischen tripeldeckersandwich-komplexes

The paramagnetic tripledecker sandwich [C₅H₅]Ni[C₂B₂(C₂H₅)₄CCH₃]Ni[C₅H₅] (I) gives NMR instead of ESR spectra. Its ¹H, ¹¹B and ¹³C signals cover spectral ranges of about 60, 1900, and 1000 ppm; the assignment is assured by selective decoupling and a series of ¹H spectra obtained from mixtures of I and its anion II. II prepared by reduction of I with potassium is the diamagnetic reference molecule for I. Paramagnetic NMR shows I to behave like metallocenes. On the NMR time scale the unpaired electron is equally distributed on both nickel atoms. Spin density delocalization from the metals to the bridging and the terminal ligand occurs by different mechanisms.     

Crystal and molecular structures of (η-xanthene)- (η-cyclopentadienyl)iron(II) hexafluorophosphate and (η-2-methylthianthrene)(η-cyclopentadienyl)iron(II) hexafluorophosphate

The neutral complexes (η⁵-C₅H₅NiXL (X = Cl, L = PPh₃ (I); L = PCy₃ (II); X = Br, L = PPh₃ (III); L = PCy₃ (IV); X = I, L = PPh₃ (V); L = PCy₃ (VI)) have been obtained by treating NiX₂L₂ with thallium cyclopentadienide. The same reaction in the presence of TlBF₄ gives cationic derivatives [(η⁵-C₅H₅)NiL₂]BF₄ (L = 2PPh₂Me (VII); L = dppe (VIII)), whereas mononuclear complexes containing two different ligands (L₂ = PPh₃ + PCy₃ (IX)) or dinuclear [(η⁵-C₅H₅)Ni(PPh₃)]₂dppe(BF₄)₂ (X) are obtained from the reaction of III with TlBF₄ in the presence of a different ligand. Reduction of cationic complexes with Na/Hg gives very unstable nickel(I) derivatives (η⁵-C₅H₅)NiL₂, which could not be isolated purely. Similar reduction of neutral complexes under CO gives a mixture of decomposition products containing [(η⁵-C₅H₅)Ni(CO)]₂ and nickel(o) carbonyls, whereas in the presence of acetylenes, dinuclear [(η⁵-C₅H₅)Ni]₂(RCCR′) (R = R′ = Ph; R = Ph, R′ = H) are obtained.     

Dithiocarbamate complexes of cyclopentadienylcobalt(III), [Co(η-C5H5)(L)(S2CNR2)] (L = ligand)

The reactions of [Co(η-C₅H₅)(L)I₂] with Na[S₂CNR₂] (R = alkyl or phenyl) give [Co(η-C₅H₅)(I)(S₂CNR₂)] (I) when L = CO and [Co(η-C₅H₅)(L)(S₂CNR₂)]I (II) when L is a tertiary phosphine, phosphite or stibine, or organo-isocyanide ligand. In similar reactions [Co(η-C₅H₅)(CO)(C₃F₇)I] gives [Co(η-C₅H₅)(C₃F₇)(S₂CNMe₂)] and [Mn(η-MeC₅H₄)(CO)₂(NO)]PF₆ forms [Mn(η-MeC₅H₄)(NO)(S₂CNR₂)]. The iodide ligands in I may be displaced by L, to give II, or by other ligands such as [CN]^?, [NCS]^?, H₂O or pyridine whilst SnCl₂ converts it to SnCl₂I. The iodide counter-anion in II may be replaced by others to give [BPh₄]^?, [Co(CO)₄]^? or [NO₃]^? salts. However [CN]^? acts differently and displaces (PhO)₃P from [Co(η-C₅H₅){P(OPh)₃}(S₂CNMe)]I to give [Co(η-C₅H₅)(CN)(S₂CNMe₂)] which may be alkylated reversibly by MeI and irreversibly by MeSO₃F to [Co(η-C₅H₅)(CNMe)(S₂CNMe₂)]⁺ salts. Conductivity measurements suggest that solutions of I in donor solvents are partially ionized with the formation of [Co(η-C₅H₅)(solvent)(S₂CNR₂)]⁺ I^? species. The IR and ¹H NMR spectra of the various complexes are reported. They are consistent with pseudo-octahedral “pianostool” molecular structures in which the bidentate dithiocarbamate ligands are coordinated to the metal atoms through both sulphur atoms.     

Basische metalle : XXXVII. Zur reaktivität der ethylen(hydrido)rhodium-komplexe [C5H5RhH(C2H4)PR3]X gegenüber nucleophilen: insertion versus substitution

The complex [C₅H₅RhH(C₂H₄)PMe₃]BF₄ (I) reacts with NaF and NaCN by deprotonation to give C₅H₅Rh(PMe₃)C₂H₄ but with NaCl, NaBr and NaI the ethylrhodium compounds C₅H₅RhC₂H₅(PMe₃)X (II–IV) are obtained. The reactions of I with CO and PPrⁱ₃ yield the BF₄ salts of the cations [C₅H₅RhH(CO)PMe₃]⁺ and [C₅H₅RhH(PPrⁱ₃)PMe₃]⁺ (V, VI), respectively, from which the uncharged complexes C₅H₅Rh(CO)PMe₃ (VII) and C₅H₅Rh(PPRⁱ₃)PMe₃ (VIII) are prepared. The carbonyl compound VII is also accessible either from C₅H₅Rh(CO)₂ and PMe₃ or from C₅H₅Rh(PMe₃)₂ and CO. The reaction of I with ethylene leads to the BF₄ salt of the cation [C₅H₅RhC₂H₅(PMe₃)C₂H₄]⁺ (X) which on treatment with PMe₃ forms the complex [C₅H₅RhC₂H₅(PMe₃)C₂H₄PMe₃]BF₄ (XI). The compound [C₅H₅RhH(C₂H₄)PPrⁱ₃]BF₄ (XII) reacts with NaI by insertion to yield C₅H₅RhC₂H₅(PPrⁱ₃)I (XIII) whereas with PPrⁱ₃ the salt [C₅H₅RhH(PPrⁱ₃)₂]BF₄ (XIV) is produced. The bis(triisopropylphosphine) complex C₅H₅Rh(PPrⁱ₃)₂ (XVI) is obtained from XIV and NaH.     

邻异丙硫基苯甲酰基和苯硫甲基铁衍生物的合成与反应

利用异丙基苯硫醚与丁基锂反应后,再依次与羰基铁和碘反应制得了碘桥双核邻异丙硫基苯甲酰基铁配合物[（o-ⁱPrS）C₆H₄COFe（CO）₂I]2,而苯甲硫醚类似的反应却仅得到单核苯硫甲基铁配合物C₆H₅SCH₂Fe（CO）₃I。当与亲核试剂作用时,这2个化合物表现出显著不同的反应活性。如双核配合物[（o-ⁱPrS）C₆H₄COFe（CO）₂I]2与2-吡啶硫醇钠（PySNa）反应得到单核配合物（o-ⁱPrS）C₆H₄COFe（CO）₂（SPy）,但单核配合物C₆H₅SCH₂Fe（CO）₃I与PySNa反应导致其分解。另一方面,单核配合物C₆H₅SCH₂Fe（CO）₃I与三苯基膦（PPh₃）反应得到羰基取代配合物C₆H₅SCH₂Fe（CO）₂（PPh₃）I,但是双核配合物[（o-ⁱPrS）C₆H₄COFe（CO）₂I]2类似的反应却导致其分解,没有获得可表征的化合物。所有新合成的化合物都通过了核磁与红外光谱的表征,它们的结构也获得了X射线单晶衍射的确证。     

邻异丙硫基苯甲酰基和苯硫甲基铁衍生物的合成与反应

利用异丙基苯硫醚与丁基锂反应后,再依次与羰基铁和碘反应制得了碘桥双核邻异丙硫基苯甲酰基铁配合物[（o-ⁱPrS） C₆H₄COFe（CO）₂I]₂,而苯甲硫醚类似的反应却仅得到单核苯硫甲基铁配合物C₆H₅SCH₂Fe（CO）₃I。当与亲核试剂作用时,这2个化合物表现出显著不同的反应活性。如双核配合物[（o-ⁱPrS） C₆H₄COFe（CO）₂I]₂与2-吡啶硫醇钠（PySNa）反应得到单核配合物（o-ⁱPrS） C₆H₄COFe（CO）₂（SPy）,但单核配合物C₆H₅SCH₂Fe（CO）₃I与PySNa反应导致其分解。另一方面,单核配合物C₆H₅SCH₂Fe（CO）₃I与三苯基膦（PPh₃）反应得到羰基取代配合物C₆H₅SCH₂Fe（CO）₂（PPh₃） I,但是双核配合物[（o-ⁱPrS） C₆H₄COFe（CO）₂I]₂类似的反应却导致其分解,没有获得可表征的化合物。所有新合成的化合物都通过了核磁与红外光谱的表征,它们的结构也获得了X射线单晶衍射的确证。     

Perchloratobis(pentafluorophenyl)triphenylphosphinegold(III) as a precursor of new gold complexes

The perchlorato ligand of perchloratobis(pentafluorophenyl)triphenylphosphinegold(III) can easily be displaced by different types of ligands. Neutral complexes are obtained by adding anionic ligands (N^?₃, HCO^?₃, while cationic complexes are obtained by adding neutral monodentate ligands (OPPh₃, OAsPh₃, ONC₅H₅, ONC₉H₇, NC₉H₇, PEt₃, PBu₃, PPh₂Me). Only with very weak σ-donors (SO₂, CO₂, NC₅F₅, NC₅Cl₅) does no reaction take place. The addition of neutral bidentate ligands leads to cationic gold(III) complexes with diphosphines and diarsines, whereas nitrogen- or oxygen-donors give rise to reductive elimination reactions which lead to gold(I) complexes.No reaction takes place with mono-olefins while cyclopolyolefins give rather unstable gold(I) complexes which readily decompose. Only the gold(I) complex with 1,5-cyclooctadiene can be isolated.     

Supramolecular Assemblies in Salts of 2,2＇-Biimidazole with 5-Sulfosalicylic Acid and 3,4,5-Trihydroxybenzoic Acid

Supramolecular assemblies of 2,2＇-biimidazole with 5-sulfosalicylic acid and 3,4,5-trihydroxybenzoic acid, have been synthesized and characterized by single-crystal X-ray diffraction methods. Both the two proton-transfer compounds of 2,2＇-biimidazole with 3-carboxy-4-hydroxybenzenesulfonic acid （5-sulfosalicylic acid, 5-SSA） [namely bis（2-（2-1H-imidazolyl）-1H-imidazolium） 4-hydroxybenzene-3-carboxylate-1-sulfonate monohydrate, 2（C6HTN4）^＋· CTH4068^2-.H2O, （Ⅰ）] and 3,4,5-trihydroxybenzoic acid [namely 2,2＇-bi-1H-imidazolium bis（3,4,5-trihydroxybenzoate） tetrahydrate, C6H8N4^2＋ ·2（C7H5O5）^-·4（H20）, （Ⅱ）] feature extensively hydrogen-bonded three-dimensional network structures having significant interlayer n-n interactions between the cation and anion species. In Ⅰ, a 5-SSA^2- dianionic species results from deprotonation of both the sulfonic and the carboxylic acid groups, all available O-atom acceptors interact with all cation and water molecule donors by hydrogen bonds. In Ⅱ, the formula unit displays a crystallographic inversion symmetry. The structural information about the two complexes between 2,2＇-biimidazole compound and benzenecarboxylic acids obtained in this work will be particularly important for the rational design of supramolecular organic functional materials.     

Alkynethiolate ligands in the syntheses of iron carbonyl derivatives. Crystal structure of [(η-C5H5)Fe(CO)2(SCCSiMe3)]

The complexes [(η⁵-C₅H₅)Fe(CO)₂(SCCR)] (R=^tBu, SiMe₃) have been obtained by reaction of [(η⁵-C₅H₅)Fe(CO)₂I] and the corresponding LiSCCR. These are the first examples of mononuclear iron compounds containing alkynethiolate ligands. The crystal structure of [(η⁵-C₅H₅)Fe(CO)₂(SCCSiMe₃)] has been determined by X-ray diffraction. The role of [(η⁵-C₅H₅)Fe(CO)₂(SCCSiMe₃)] as a metalloligand in its reactions with metal carbonyls has been explored.     

On the properties of binuclear cyclopentadienyl-fulvalene-nitrene complexes of Nb

The properties of (η⁵:η⁵-C₅H₄C₅H₄)(C₅H₅)₂Nb₂(μ-NC₆H₅)₂ (I) have been investigated. Reaction of I with acids (HCl, H₂SO₄ and CX₃COOH) includes diprotonation to form the dication, [(η⁵:η⁵-C₅H₄C₅H₄)(C₅H₅)₂Nb_2^? (μ-NC₆H₅)₂H₂]²⁺ (II). The process is reversible and the initial neutral compound I may be recovered under the action of a base. The protonated compound II may lose NC₆H₅ ligands as C₆H₅NH₃⁺; the paramagnetic product of the dissociation (C₅H₄C₅H₄)(C₅H₅)₂Nb₂Cl₄ (III) has been isolated.     

Hexahydroxojod(VII)-Salze

Hexahydroxoiodine(VII) Salts. H₅IO₆ reacts with concentrated H₂SO₄ and concentrated H₂SeO₄ forming the compounds H₅IO₆ · H₂SO₄ and H₅IO₆ · H₂SeO₄, respectively. As shown by their RAMAN spectra, these compounds are salts [I(OH) ₆]HSO₄ and [I(OH) ₆]HSeO₄ containing the hexahydroxoiodine(VII) cation [I(OH) ₆]⁺· Under particular conditions furthermore [I(OH) ₆]₂SO₄ has been obtained.     

Two succinic acid derivatives of 2‐ethyl‐6‐methylpyridin‐3‐ol

Crystals of bis(2‐ethyl‐3‐hydroxy‐6‐methylpyridinium) succinate–succinic acid (1/1), C₈H₁₂NO⁺·0.5C₄H₄O₄²⁻·0.5C₄H₆O₄, (I), and 2‐ethyl‐3‐hydroxy‐6‐methylpyridinium hydrogen succinate, C₈H₁₂NO⁺·C₄H₅O₄⁻, (II), were obtained by reaction of 2‐ethyl‐6‐methylpyridin‐3‐ol with succinic acid. The succinate anion and succinic acid molecule in (I) are located about centres of inversion. Intermolecular O—H...O, N—H...O and C—H...O hydrogen bonds are responsible for the formation of a three‐dimensional network in the crystal structure of (I) and a two‐dimensional network in the crystal structure of (II). Both structures are additionally stabilized by π–π interactions between symmetry‐related pyridine rings, forming a rod‐like cationic arrangement for (I) and cationic dimers for (II).     

Purine 3′:5′‐cyclic nucleotides with the nucleobase in a syn orientation: cAMP,cGMP and cIMP

Purine 3′:5′‐cyclic nucleotides are very well known for their role as the secondary messengers in hormone action and cellular signal transduction. Nonetheless, their solid‐state conformational details still require investigation. Five crystals containing purine 3′:5′‐cyclic nucleotides have been obtained and structurally characterized, namely adenosine 3′:5′‐cyclic phosphate dihydrate, C₁₀H₁₂N₅O₆P·2H₂O or cAMP·2H₂O, (I), adenosine 3′:5′‐cyclic phosphate 0.3‐hydrate, C₁₀H₁₂N₅O₆P·0.3H₂O or cAMP·0.3H₂O, (II), guanosine 3′:5′‐cyclic phosphate pentahydrate, C₁₀H₁₂N₅O₇P·5H₂O or cGMP·5H₂O, (III), sodium guanosine 3′:5′‐cyclic phosphate tetrahydrate, Na⁺·C₁₀H₁₁N₅O₇P⁻·4H₂O or Na(cGMP)·4H₂O, (IV), and sodium inosine 3′:5′‐cyclic phosphate tetrahydrate, Na⁺·C₁₀H₁₀N₄O₇P⁻·4H₂O or Na(cIMP)·4H₂O, (V). Most of the cyclic nucleotide zwitterions/anions [two from four cAMP present in total in (I) and (II), cGMP in (III), cGMP⁻ in (IV) and cIMP⁻ in (V)] are syn conformers about the N‐glycosidic bond, and this nucleobase arrangement is accompanied by C_rib—H…N_pur hydrogen bonds (rib = ribose and pur = purine). The base orientation is tuned by the ribose pucker. An analysis of data obtained from the Cambridge Structural Database made in the context of syn–anti conformational preferences has revealed that among the syn conformers of various purine nucleotides, cyclic nucleotides and dinucleotides predominate significantly. The interactions stabilizing the syn conformation have been indicated. The inter‐nucleotide contacts in (I)–(V) have been systematized in terms of the chemical groups involved. All five structures display three‐dimensional hydrogen‐bonded networks.     

Stoichiometric vs Catalytic MeLi Reaction with the Mixture of (ẽ5‐C5H5)Fe(CO)2l and P(OR)3: Nucleophilic Methylation vs Arbuzov‐Like Dealkylation

The reaction of stoichiometric MeLi with the 1:1 mixture of (?⁵‐C₅H₅)Fe(CO)₂I/P(OR)₃ (R = Me, Et, and Ph) at ?78°C changes the bonding mode between metal and ring from (?⁵‐C₅H₅) to (?⁴‐exo‐MeC₅H₅) and the oxidation state of metal from Fe(II) to Fe(O), the novel complexes (?⁴‐exo‐MeC₅H₅)Fe(CO)₂P(C)R)₃ being obtained in 45‐57% yields. The reaction of trace MeLi with the 1:1 mixture of (?⁵‐C₅H₅)Fe(CO)₂I/P(OMe)₃ at ?78°C results in 70% yield of the phosphonate complex (?⁵‐C₅H₅)Fe(CO)₂P(O)(OMe)₂ which is an Arbuzov‐like dealkylation product from the cationic intermediate [(?⁵‐C₅H₅)Fe(CO)₂P(OMe)₃⁺] and the iodide. The amines could assist the Arbuzov‐like dealkylation of [(?⁵‐C₅H₅)Fe(CO)₂P(OMe)₃⁺] [PF₆^?] where iron‐carbamoyl intermediates are likely involved in the case of primary amines.     

Basische metalle: LII. Synthese von carbenoid- und ylidcobalt(III)-komplexen aus substitutionslabilen cobalt(I)-vorstufen

The cyclopentadienylcobalt(I) compounds C₅H₅Co(PMe₃)P(OR)₃ (R = Me, Et, Prⁱ) and C₅H₅Co(C₂H₄)L (L = PMe₃, P(OMe)₃, CO) are prepared by ligand substitution starting from C₅H₅Co(PMe₃)₂ and C₅H₅Co(C₂H₄)₂. Whereas the reaction of C₅H₅Co(PMe₃)P(OMe)₃ with CH₂Br₂ mainly gives [C₅H₅CoBr(PMe₃)P(OMe)₃]Br, the dihalogenocobalt(III) complexes C₅H₅CoX₂(PMe₃) (X = Br, I) are obtained from C₅H₅Co(CO)PMe₃ and CH₂X₂. Treatment of C₅H₅Co(CO)PMe₃ or C₅H₅Co(C₂H₄)PMe₃ with CH₂ClI at low temperatures produces a mixture of C₅H₅CoCH₂Cl(PMe₃)I and C₅H₅CoCl(PMe₃)I, which can be separated due to their different solubilities. The same reaction in the presence of ligand L gives the carbenoidcobalt(III) compounds [C₅H₅CoCH₂Cl(PMe₃)L]PF₆ in nearly quantitative yields. If NEt₃ is used as the Lewis base, the ylide complexes [C₅H₅Co(CH₂PMe₃)(PMe₃)X]PF₆ (X = Br, I) are obtained. The PF₆ salts of the dications [C₅H₅Co(CH₂PMe₃)(PMe₃)L]²⁺ (L = PMe₃, P(OMe)₃, CNMe) and [C₅H₅Co(CH₂PMe₃)(P(OMe)₃)₂]²⁺ are prepared either from [C₅H₅Co(CH₂PMe₃)(PMe₃)X]⁺ and L, or more directly from C₅H₅Co(CO)PMe₃, CH₂X₂ and PMe₃ or P(OMe)₃, respectively. The synthesis of C₅H₅CoCH₂OMe(PMe₃)I is also described.     

β‐Pyridinium di­chloro­iodide

The β modification of pyridinium di­chloro­iodide, C₅H₆N⁺·Cl₂I^?, was obtained as yellow crystals by the reaction of (C₅NH₅)AuCl₃, C₅H₆N⁺·Cl^? and I₂ in a vacuum‐sealed ampoule. The di­chloro­iodide ion is nearly symmetric and linear with I—Cl bond lengths of 2.544 (3) and 2.550 (3) Å and a Cl—I—Cl angle of 179.68 (12)°.