The cocrystal rac‐1‐[(N,4‐dimethylbenzenesulfonamido)methyl]‐2‐(diphenylphosphoryl)ferrocene–rac‐1‐[(N,4‐dimethylbenzenesulfonamido)methyl]‐2‐(diphenylphosphanyl)ferrocene (0.45/0.55)

As part of our interest in the synthesis and catalytic applications of chiral (diphenylphosphanyl)ferrocene ligands, we designed a number of P,N‐containing ligands for use in asymmetric transfer hydrogenation (ATH). During the synthetic procedure to obtain rac‐1‐[(N,4‐dimethylbenzenesulfonamido)methyl]‐2‐(diphenylphosphanyl)ferrocene, the title compound, [Fe(C₅H₅)(C₂₆H₂₅NO₂PS)]_0.55·[Fe(C₅H₅)(C₂₆H₂₅NO₃PS)]_0.45, was obtained as a by‐product. It is composed of a ferrocene group disubstituted by a partially oxidized diphenylphosphanyl group, as confirmed by ³¹P NMR analysis, and an (N,4‐dimethylbenzenesulfonamido)methyl substituent. Owing to the partially oxidized diphenylphosphanyl group, it is best to view the crystal as being composed of a mixture of non‐oxidized and oxidized phosphane, so it can be regarded as a cocrystal. It is also a racemate. To the best of our knowledge, the P=O distance [1.344 (4) Å] is the shortest observed for related (diphenylphosphoryl)ferrocene compounds. The packing is stabilized by weak C—H...O interactions, forming R₂²(10) hydrogen‐bonding motifs, which build up a chain along the c axis.     

Hemilability and structural considerations in complexes of platinum(II) comprising bis(diphenylphosphanyl)methane monoxide,monosulfide, and monoselenide

The structure of a platinum(II) complex containing (R)-(dimethylamino)ethylnapthyl and bis(diphenylphosphanyl)methane monosulfide ligands, namely, {(R)-1-[1-(dimethylamino)ethyl]napthyl-κ²N,C²}[(diphenylphosphanylmethyl)diphenylphosphine sulfide-κ²P,S]platinum(II) hexafluoridoantimonate dichloromethane monosolvate, [Pt(C₁₄H₁₆N)(C₂₅H₂₂P₂S)][SbF₆]·CH₂Cl₂, was determined. The structural features are compared with analogous platinum bis(diphenylphosphanyl)methane monoxide [dppm(O)] and bis(diphenylphosphanyl)methane monoselenide [dppm(Se)] complexes in relation to their potential hemilability and stereochemical nonrigidity.     

Two precatalysts for application in asymmetric homogeneous hydrogenation

The title compounds, [(1R,1′R,2R,2′R)‐2,2′‐bis(diphenylphosphanyl)‐1,1′‐dicyclopentane](η⁴‐norbornadiene)rhodium(I) tetrafluoridoborate, [Rh(C₃₄H₃₆P₂)(C₇H₈)]BF₄, (I), and [(1R,1′R,2R,2′R)‐2,2′‐bis(diphenylphosphanyl)‐1,1′‐dicyclopentane][η⁴‐(Z,Z)‐cycloocta‐1,5‐diene]rhodium(I) tetrafluoridoborate dichloromethane monosolvate, [Rh(C₃₄H₃₆P₂)(C₈H₁₂)]BF₄·CH₂Cl₂, (II), are applied as precatalysts in asymmetric homogeneous hydrogenation, e.g. in the reduction of dehydroamino acids, affording excellent enantiomeric excesses [Zhu, Cao, Jiang & Zhang (1997). J. Am. Chem. Soc. 119 , 1799–1800].     

Asymmetric diosmium sawhorse complexes

Three asymmetric diosmium(I) carbonyl sawhorse complexes have been prepared by microwave heating. One of these complexes is of the type Os₂(μ‐O₂CR)(μ‐O₂CR′)(CO)₄L₂, with two different bridging carboxylate ligands, while the other two complexes are of the type Os₂(μ‐O₂CR)₂(CO)₅L, with one axial CO ligand and one axial phosphane ligand. The mixed carboxylate complex Os₂(μ‐acetate)(μ‐propionate)(CO)₄[P(p‐tolyl)₃]₂, ( 1 ), was prepared by heating Os₃(CO)₁₂ with a mixture of acetic and propionic acids, isolating Os₂(μ‐acetate)(μ‐propionate)(CO)₆, and then replacing two CO ligands with two phosphane ligands. This is the first example of an Os₂ sawhorse complex with two different carboxylate bridges. The syntheses of Os₂(μ‐acetate)₂(CO)₅[P(p‐tolyl)₃], ( 3 ), and Os₂(μ‐propionate)₂(CO)₅[P(p‐tolyl)₃], ( 6 ), involved the reaction of Os₃(CO)₁₂ with the appropriate carboxylic acid to initially produce Os₂(μ‐carboxylate)₂(CO)₆, followed by treatment with refluxing tetrahydrofuran (THF) to form Os₂(μ‐carboxylate)₂(CO)₅(THF), and finally addition of tri‐p‐tolylphosphane to replace the THF ligand with the P(p‐tolyl)₃ ligand. Neutral complexes of the type Os₂(μ‐O₂CR)₂(CO)₅L had not previously been subjected to X‐ray crystallographic analysis. The more symmetrical disubstituted complexes, i.e. Os₂(μ‐formate)₂(CO)₄[P(p‐tolyl)₃]₂, ( 8 ), Os₂(μ‐acetate)₂(CO)₄[P(p‐tolyl)₃]₂, ( 4 ), and Os₂(μ‐propionate)₂(CO)₄[P(p‐tolyl)₃]₂, ( 7 ), as well as the previously reported symmetrical unsubstituted complexes Os₂(μ‐acetate)₂(CO)₆, ( 2 ), and Os₂(μ‐propionate)₂(CO)₆, ( 5 ), were also prepared in order to examine the influence of axial ligand substitution on the Os—Os bond distance in these sawhorse molecules. Eight crystal structures have been determined and studied, namely μ‐acetato‐1κO:2κO′‐μ‐propanoato‐1κO:2κO′‐bis[tris(4‐methylphenyl)phosphane]‐1κP,2κP′‐bis(dicarbonylosmium)(Os—Os) dichloromethane monosolvate, [Os₂(C₂H₃O₂)(C₃H₅O₂)(C₂₁H₂₁P)₂(CO)₄]·CH₂Cl₂, ( 1 ), bis(μ‐acetato‐1κO:2κO′)bis(tricarbonylosmium)(Os—Os), [Os₂(C₂H₃O₂)₂(CO)₆], ( 2 ) (redetermined structure), bis(μ‐acetato‐1κO:2κO′)pentacarbonyl‐1κ²C,2κ³C‐[tris(4‐methylphenyl)phosphane‐1κP]diosmium(Os—Os), [Os₂(C₂H₃O₂)₂(C₂₁H₂₁P)(CO)₅], ( 3 ), bis(μ‐acetato‐1κO:2κO′)bis[tris(4‐methylphenyl)phosphane]‐1κP,2κP‐bis(dicarbonylosmium)(Os—Os) p‐xylene sesquisolvate, [Os₂(C₂H₃O₂)₂(C₂₁H₂₁P)₂(CO)₄]·1.5C₈H₁₀, ( 4 ), bis(μ‐propanoato‐1κO:2κO′)bis(tricarbonylosmium)(Os—Os), [Os₂(C₃H₅O₂)₂(CO)₆], ( 5 ), pentacarbonyl‐1κ²C,2κ³C‐bis(μ‐propanoato‐1κO:2κO′)[tris(4‐methylphenyl)phosphane‐1κP]diosmium(Os—Os), [Os₂(C₃H₅O₂)₂(C₂₁H₂₁P)(CO)₅], ( 6 ), bis(μ‐propanoato‐1κO:2κO′)bis[tris(4‐methylphenyl)phosphane]‐1κP,2κP‐bis(dicarbonylosmium)(Os—Os) dichloromethane monosolvate, [Os₂(C₃H₅O₂)₂(C₂₁H₂₁P)₂(CO)₄]·CH₂Cl₂, ( 7 ), and bis(μ‐formato‐1κO:2κO′)bis[tris(4‐methylphenyl)phosphane]‐1κP,2κP‐bis(dicarbonylosmium)(Os—Os), [Os₂(CHO₂)₂(C₂₁H₂₁P)₂(CO)₄], ( 8 ).     

Dichlorido[(S,RS)‐1‐diphenylphosphino‐2‐(ethylsulfanylmethyl)ferrocene]palladium(II)

The reaction of enantiomerically pure planar chiral ferrocene phosphine thioether with bis(acetonitrile)dichloridopalladium yields the title square‐planar mononuclear palladium complex as an enantiomerically pure single diastereoisomer, [PdFe(C₅H₅)(C₂₀H₂₀PS)Cl₂]. The planar chirality of the ligand is retained in the complex and fully controls the central chirality on the S atom. The absolute configuration, viz. S for the planar chirality and R for the S atom, is unequivocally determined by refinement of the Flack parameter.     

Two precatalysts for application in propargylic CH activation

The complexes {bis[(2‐diphenylphosphanyl)phenyl] ether‐κ²P,P′}(η⁴‐norbornadiene)rhodium(I) tetrafluoridoborate, [Rh(C₇H₈)(C₃₆H₂₈OP₂)]BF₄, and {bis[(2‐diphenylphosphanyl)phenyl] ether‐κ²P,P′}[η⁴‐(Z,Z)‐cycloocta‐1,5‐diene]rhodium(I) tetrafluoridoborate dichloromethane monosolvate, [Rh(C₈H₁₂)(C₃₆H₂₈OP₂)]BF₄·CH₂Cl₂, are applied as precatalysts in redox‐neutral atomic‐economic propargylic CH activation [Lumbroso et al. (2013). Angew. Chem. Int. Ed. 52 , 1890–1932]. In addition, the catalytically inactive pentacoordinated 18‐electron complex {bis[(2‐diphenylphosphanyl)phenyl] ether‐κ²P,P′}chlorido(η⁴‐norbornadiene)rhodium(I), [RhCl(C₇H₈)(C₃₆H₂₈OP₂)], was synthesized, which can form in the presence of chloride in the reaction system.     

New isostructural transition metal complexes with a non‐innocent dithiolate ligand

Three new complexes with 3,6‐dichlorobenzene‐1,2‐dithiol (bdtCl₂), namely methyltriphenylphosphonium bis(3,6‐dichlorobenzene‐1,2‐dithiolato‐κ²S,S′)cobaltate(1−), (C₁₉H₁₈P)[Co(C₆H₂Cl₂S₂)₂], (I), bis(methyltriphenylphosphonium) bis(3,6‐dichlorobenzene‐1,2‐dithiolato‐κ²S,S′)cuprate(2−) dimethyl sulfoxide disolvate, (C₁₉H₁₈P)₂[Cu(C₆H₂Cl₂S₂)₂]·2C₂H₆OS, (II), and methyltriphenylphosphonium bis(3,6‐dichlorobenzene‐1,2‐dithiolato‐κ²S,S′)cuprate(1−), (C₁₉H₁₈P)[Cu(C₆H₂Cl₂S₂)₂], (III), have been synthesized and characterized by single‐crystal X‐ray diffraction. The X‐ray structure analyses of all three complexes confirm that the four donor S atoms form a slightly distorted square‐planar coordination arrangement around the central metal atom. An interesting finding for both the Cu^II and Cu^III complexes, i.e. (II) and (III), respectively, is that the coordination polyhedra are principally the same and differ only slightly with respect to the interatomic distances.     

Preparation of planar‐chiral multidonor phosphanylferrocene carboxamides and their application as ligands for palladium‐catalysed asymmetric allylic alkylation

Amide coupling of (S_p)‐2‐(diphenylphosphanyl)ferrocene‐1‐carboxylic acid with appropriate terminal amines mediated by 1‐hydroxybenzotriazole and a carbodiimide affords multi‐donor amides terminally functionalized with planar‐chiral (S_p)‐2‐(diphenylphosphanyl)ferrocen‐1‐yl moieties in good to excellent yields. Palladium catalysts based on these ligands efficiently promote asymmetric allylic alkylation of 1,3‐diphenylallyl acetate with in situ generated dimethyl malonate anion to give the C‐alkylated product with ees up to 93% at room temperature. Copyright © 2010 John Wiley & Sons, Ltd.     

Synthesis,Structures, and Photophysics of Polynuclear Silver(I) Thiolate and Silver(I) Thiocarboxylate Complexes with Dppm Ligands

Trinuclear silver(I) thiolate and silver(I) thiocarboxylate complexes [Ag₃(μ‐dppm)₃(μ_n‐SR)₂](ClO₄) [n = 2, R = C₆H₄Cl‐4 ( 1 ) and C{O}Ph ( 2 ); n = 3, R = tBu ( 3 )], pentanuclear silver(I) thiolate complex [Ag₅(μ‐dppm)₄(μ₃‐SC₆H₄NO₂‐4)₄](PF₆) ( 4 ), and hexanuclear silver(I) thiolate complexes [Ag₆(μ‐dppm)₄(μ₃‐SR)₄]Y₂ [Y = ClO₄, R =C₆H₄CH₃‐4 ( 5 ) and C₁₀H₇ (2‐naphthyl) ( 7 ); Y = PF₆, R = C₆H₄OCH₃‐4( 6 )], were synthesized [dppm = bis(diphenylphosphanyl)methane] and their crystal structures as well as photophysical properties were studied. In the solid state at 77 K, trinuclear silver(I) thiolate and silver(I) thiocarboxylate complexes 1 and 2 exhibit luminescence at 470–523 nm, tentatively attributed to originate from the ³IL (intraligand) of thiolate or thiocarboxylate ligands, whereas hexanuclaer silver(I) thiolate complexes 5 and 7 produce dual emission, in which high‐energy emission is tentatively attributed to come from the ³IL of thiolate ligands and low‐energy emission is tentatively assigned to come from the admixture of metal ··· metal bond‐to‐ligand charge‐transfer (MMLCT) and metal‐centered (MC) excited states.     

Three new dihydro‐β‐agarofuran sesquiterpenes from the seeds of Maytenus boaria

As part of a project studying the secondary metabolites extracted from the Chilean flora, we report herein three new β‐agarofuran sesquiterpenes, namely (1S,4S,5S,6R,7R,8R,9R,10S)‐6‐acetoxy‐4,9‐dihydroxy‐2,2,5a,9‐tetramethyloctahydro‐2H‐3,9a‐methanobenzo[b]oxepine‐5,10‐diyl bis(furan‐3‐carboxylate), C₂₇H₃₂O₁₁, ( II ), (1S,4S,5S,6R,7R,9S,10S)‐6‐acetoxy‐9‐hydroxy‐2,2,5a,9‐tetramethyloctahydro‐2H‐3,9a‐methanobenzo[b]oxepine‐5,10‐diyl bis(furan‐3‐carboxylate), C₂₇H₃₂O₁₀, ( III ), and (1S,4S,5S,6R,7R,9S,10S)‐6‐acetoxy‐10‐(benzoyloxy)‐9‐hydroxy‐2,2,5a,9‐tetramethyloctahydro‐2H‐3,9a‐methanobenzo[b]oxepin‐5‐yl furan‐3‐carboxylate, C₂₉H₃₄O₉, ( IV ), obtained from the seeds of Maytenus boaria and closely associated with a recently published relative [Paz et al. (2017). Acta Cryst. C 73 , 451–457]. In the (isomorphic) structures of ( II ) and ( III ), the central decalin system is esterified with an acetate group at site 1 and furoate groups at sites 6 and 9, and differ at site 8, with an OH group in ( II ) and no substituent in ( III ). This position is also unsubstituted in ( IV ), with site 6 being occupied by a benzoate group. The chirality of the skeletons is described as 1S,4S,5S,6R,7R,8R,9R,10S in ( II ) and 1S,4S,5S,6R,7R,9S,10S in ( III ) and ( IV ), matching the chirality suggested by NMR studies. This difference in the chirality sequence among the title structures (in spite of the fact that the three skeletons are absolutely isostructural) is due to the differences in the environment of site 8, i.e. OH in ( II ) and H in ( III ) and ( IV ). This diversity in substitution, in turn, is responsible for the differences in the hydrogen‐bonding schemes, which is discussed.     

1,2‐Bis[(pyridin‐2‐ylmethyl)sulfanyl]ethane and its dimorphic hydrochloride salt

Although having been described as a liquid in the literature for 41 years, 1,2‐bis[(pyridin‐2‐ylmethyl)sulfanyl]ethane, C₁₄H₁₆N₂S₂, (I), has now been obtained as monoclinic crystals via a new and convenient method of purification. Molecules of (I) are located on crystallographic inversion centres and are held together by C—H...N and C—H...S interactions, resulting in the formation of a three‐dimensional network structure. In addition, two polymorphs of the corresponding hydrochloride salt, 2‐[({2‐[(pyridin‐1‐ium‐2‐ylmethyl)sulfanyl]ethyl}sulfanyl)methyl]pyridin‐1‐ium dichloride, C₁₄H₁₈N₂S₂²⁺·2Cl⁻, (II) and (III), have been isolated. Molecules of (II) and (III) have similar conformations and are located on inversion centres. Both polymorphs form three‐dimensional networks through N—H...Cl, C—H...Cl and C—H...S interactions. The structure of (III) displays voids of 35 ų.     

Conformational change induced by hydration: trans‐dichloro­bis­[(1R,2R,3R,5S)‐(–)‐isopinocampheylamine]palladium(II) and trans‐dichloro­bis[(1S,2S,3S,5R)‐(+)‐isopinocampheylamine]palladium(II) hemihydrate

The title compounds, trans‐dichloro­bis[(1R,2R,3R,5S)‐(−)‐2,6,6‐trimethyl­bicyclo­[3.1.1]heptan‐3‐amine]palladium(II), [PdCl₂(C₁₀H₁₉N)₂], and trans‐dichloro­bis[(1S,2S,3S,5R)‐(+)‐2,6,6‐trimethyl­bicyclo­[3.1.1]heptan‐3‐amine]palladium(II) hemihydrate, [PdCl₂(C₁₀H₁₉N)₂]·0.5H₂O, present different arrangements of the amine ligands coordinated to Pd^II, viz. antiperiplanar in the former case and (−)anticlinal in the latter. The hemihydrate is an inclusion compound, with a Pd coordination complex and disordered water mol­ecules residing on crystallographic twofold axes. The crystal structure for the hemihydrate includes a short Pd⋯Pd separation of 3.4133 (13) Å.     

Ligand‐forced dimerization of copper(I)–olefin complexes bearing a 1,3,4‐thiadiazole core

As an important class of heterocyclic compounds, 1,3,4‐thiadiazoles have a broad range of potential applications in medicine, agriculture and materials chemistry, and were found to be excellent precursors for the crystal engineering of organometallic materials. The coordinating behaviour of allyl derivatives of 1,3,4‐thiadiazoles with respect to transition metal ions has been little studied. Five new crystalline copper(I) π‐complexes have been obtained by means of an alternating current electrochemical technique and have been characterized by single‐crystal X‐ray diffraction and IR spectroscopy. The compounds are bis[μ‐5‐methyl‐N‐(prop‐2‐en‐1‐yl)‐1,3,4‐thiadiazol‐2‐amine]bis[nitratocopper(I)], [Cu₂(NO₃)₂(C₆H₉N₃S)₂], (1), bis[μ‐5‐methyl‐N‐(prop‐2‐en‐1‐yl)‐1,3,4‐thiadiazol‐2‐amine]bis[(tetrafluoroborato)copper(I)], [Cu₂(BF₄)₂(C₆H₉N₃S)₂], (2), μ‐aqua‐bis{μ‐5‐[(prop‐2‐en‐1‐yl)sulfanyl]‐1,3,4‐thiadiazol‐2‐amine}bis[nitratocopper(I)], [Cu₂(NO₃)₂(C₅H₇N₃S₂)₂(H₂O)], (3), μ‐aqua‐(hexafluorosilicato)bis{μ‐5‐[(prop‐2‐en‐1‐yl)sulfanyl]‐1,3,4‐thiadiazol‐2‐amine}dicopper(I)–acetonitrile–water (2/1/4), [Cu₂(SiF₆)(C₅H₇N₃S₂)₂(H₂O)]·0.5CH₃CN·2H₂O, (4), and μ‐benzenesulfonato‐bis{μ‐5‐[(prop‐2‐en‐1‐yl)sulfanyl]‐1,3,4‐thiadiazol‐2‐amine}dicopper(I) benzenesulfonate–methanol–water (1/1/1), [Cu₂(C₆H₅O₃S)(C₅H₇N₃S₂)₂](C₆H₅O₃S)·CH₃OH·H₂O, (5). The structure of the ligand 5‐methyl‐N‐(prop‐2‐en‐1‐yl)‐1,3,4‐thiadiazol‐2‐amine (Mepeta ), C₆H₉N₃S, was also structurally characterized. Both Mepeta and 5‐[(prop‐2‐en‐1‐yl)sulfanyl]‐1,3,4‐thiadiazol‐2‐amine (Pesta ) (denoted L ) reveal a strong tendency to form dimeric {Cu₂L ₂}²⁺ fragments, being attached to the metal atom in a chelating–bridging mode via two thiadiazole N atoms and an allylic C=C bond. Flexibility of the {Cu₂(Pesta )₂}²⁺ unit allows the Cu^I atom site to be split into two positions with different metal‐coordination environments, thus enabling the competitive participation of different molecules in bonding to the metal centre. The Pesta ligand in (4) allows the Cu^I atom to vary between water O‐atom and hexafluorosilicate F‐atom coordination, resulting in the rare case of a direct Cu^I…FSiF₅²⁻ interaction. Extensive three‐dimensional hydrogen‐bonding patterns are formed in the reported crystal structures. Complex (5) should be considered as the first known example of a Cu^I(C₆H₅SO₃) coordination compound. To determine the hydrogen‐bond interactions in the structures of (1) and (2), a Hirshfeld surface analysis has been performed.     

Syntheses and structures of one CuI‐containing coordination polymer and two macrocyclic supramolecular complexes based on flexible 1,3,4‐oxadiazole‐containing ligands

Three coordination complexes with Cu^I centres have been prepared using the symmetrical flexible organic ligands 1,3‐bis{[5‐(quinolin‐2‐yl)‐1,3,4‐oxadiazol‐2‐yl]sulfanyl}propane (L1) and 1,4‐bis{[5‐(quinolin‐2‐yl)‐1,3,4‐oxadiazol‐2‐yl]sulfanyl}butane (L2). Crystallization of L1 with Cu(SO₃CF₃)₂ and of L2 with Cu(BF₄)₂ and Cu(ClO₄)₂ in a CH₂Cl₂/CH₃OH mixed‐solvent system at room temperature afforded the coordination complexes catena‐poly[[copper(I)‐μ‐1,3‐bis{[5‐(quinolin‐2‐yl)‐1,3,4‐oxadiazol‐2‐yl]sulfanyl}propane] methanesulfonate dichloromethane 0.6‐solvate], {[Cu(C₂₅H₁₈N₆O₂S₂)](CF₃SO₃)·0.6CH₂Cl₂}_n, (I), bis(μ‐1,4‐bis{[5‐(quinolin‐2‐yl)‐1,3,4‐oxadiazol‐2‐yl]sulfanyl}butane)dicopper(I) bis(tetrafluoridoborate)–dichloromethane–methanol (1/1.5/1), [Cu₂(C₂₆H₂₀N₆O₂S₂)₂](BF₄)₂·1.5CH₂Cl₂·CH₃OH, (II), and bis(μ‐1,4‐bis{[5‐(quinolin‐2‐yl)‐1,3,4‐oxadiazol‐2‐yl]sulfanyl}butane)dicopper(I) bis(perchlorate)–dichloromethane–methanol (1/2/1), [Cu₂(C₂₆H₂₀N₆O₂S₂)₂](ClO₄)₂·2CH₂Cl₂·CH₃OH, (III). Under the control of the dumbbell‐shaped CF₃SO₃⁻ anion, complex (I) forms a one‐dimensional chain and neighbouring chains form a spiral double chain. Under the control of the regular tetrahedron‐shaped BF₄⁻ and ClO₄⁻ anions, complexes (II) and (III) have been obtained as bimetallic rings, which further interact viaπ–π interactions to form two‐dimensional networks. The anions play a decisive role in determining the arrangement of these discrete molecular complexes in the solid state.     

Intermolecular stacking in pyrazolo[3,4‐d]pyrimidine‐based pentamethylene‐linked flexible ­molecules

The crystal structures of 1‐{5‐[4,6‐bis­(methyl­sulfanyl)‐2H‐py­razolo­[3,4‐d]­pyrimidin‐2‐yl]­pentyl}‐6‐methyl­sulfanyl‐4‐(pyr­rolidin‐1‐yl)‐1H‐pyrazolo­[3,4‐d]­pyrimidine, C₂₂H₂₉N₉S₃, and 6‐methyl­sulfanyl‐1‐{5‐[6‐methyl­sulfanyl‐4‐(pyrrolidin‐1‐yl)‐2H‐pyrazolo­[3,4‐d]­pyrimidin‐2‐yl]­pentyl}‐4‐(pyrrolidin‐1‐yl)‐1H‐pyrazolo­[3,4‐d]­pyrimidine, C₂₅H₃₄N₁₀S₂, which differ in having either a pyrrolidine substituent or a methylsulfanyl group, show intermolecular stacking due to aromatic π–π interactions between the pyrazolo­[3,4‐d]­pyrimidine rings.     

catena‐Poly[[[μ‐1,3‐bis(diphenylphosphanyl)propane‐κ2P:P′][O‐ethyl (4‐methoxyphenyl)phosphonodithioato‐κ2S,S′]silver(I)] chloroform monosolvate]

Reaction of a mixture of AgOAc, Lawesson's reagent [2,4‐bis(4‐methoxyphenyl)‐1,3‐dithiadiphosphetane‐2,4‐disulfide] and 1,3‐bis(diphenylphosphanyl)propane (dppp) under ultrasonic treatment gave the title compound, {[Ag(C₉H₁₂O₂PS₂)(C₂₇H₂₆P₂)]·CHCl₃}_n, a novel one‐dimensional chain based on the in situ‐generated bipodal ligand [ArP(OEt)S₂]⁻ (Ar = 4‐methoxyphenyl). The compound consists of bidentate bridging 1,3‐bis(diphenylphosphanyl)propane (dppp) and in situ‐generated bidentate chelating [ArP(OEt)S₂]⁻ ligands. The dppp ligand links the [Ag{ArP(OEt)S₂}] subunit to form an achiral one‐dimensional infinite chain. These achiral chains are packed into chiral crystals by virtue of van der Waals interactions. No π–π interactions are observed in the crystal structure.     

A pair of diastereomeric 1:2 salts of (R)‐ and (S)‐2‐methylpiperazine with (2S,3S)‐tartaric acid

The crystal structures of a pair of diastereomeric 1:2 salts of (R)‐ and (S)‐2‐methylpiperazine with (2S,3S)‐tartaric acid, namely (R)‐2‐methylpiperazinediium bis[hydrogen (2S,3S)‐tartrate] monohydrate, (I), and (S)‐2‐methylpiperazinediium bis[hydrogen (2S,3S)‐tartrate] monohydrate, (II), both C₅H₁₄N₂²⁺·2C₄H₅O₆⁻·H₂O, each reveal the formation of well‐defined head‐to‐tail‐connected hydrogen tartrate chains; these chains are linked into a two‐dimensional sheet via intermolecular hydrogen bonds involving hydroxy groups and water molecules, resulting in a layer structure. The (R)‐2‐methylpiperazinediium ions lie between the hydrogen tartrate layers in the most stable equatorial conformation in (I), whereas in (II), these ions are in an unstable axial position inside the more interconnected layers and form a larger number of intermolecular hydrogen bonds than are observed in (I).     

Syntheses and structures of three macrocyclic supramolecular complexes and one ZnII‐containing coordination polymer generated from a semi‐rigid multidentate N‐containing ligand

Semirigid organic ligands can adopt different conformations to construct coordination polymers with more diverse structures when compared to those constructed from rigid ligands. A new asymmetric semirigid organic ligand, 4‐{2‐[(pyridin‐3‐yl)methyl]‐2H‐tetrazol‐5‐yl}pyridine ( L ), has been prepared and used to synthesize three bimetallic macrocyclic complexes and one coordination polymer, namely, bis(μ‐4‐{2‐[(pyridin‐3‐yl)methyl]‐2H‐tetrazol‐5‐yl}pyridine)bis[dichloridozinc(II)] dichloromethane disolvate, [Zn₂Cl₄(C₁₂H₁₀N₆)₂]·2CH₂Cl₂, ( I ), the analogous chloroform monosolvate, [Zn₂Cl₄(C₁₂H₁₀N₆)₂]·CHCl₃, ( II ), bis(μ‐4‐{2‐[(pyridin‐3‐yl)methyl]‐2H‐tetrazol‐5‐yl}pyridine)bis[diiodidozinc(II)] dichloromethane disolvate, [Zn₂I₄(C₁₂H₁₀N₆)₂]·2CH₂Cl₂, ( III ), and catena‐poly[[[diiodidozinc(II)]‐μ‐4‐{2‐[(pyridin‐3‐yl)methyl]‐2H‐tetrazol‐5‐yl}pyridine] chloroform monosolvate], {[ZnI₂(C₁₂H₁₀N₆)]·CHCl₃}_n, ( IV ), by solution reaction with ZnX₂ (X = Cl and I) in a CH₂Cl₂/CH₃OH or CHCl₃/CH₃OH mixed solvent system at room temperature. Complex ( I ) is isomorphic with complex ( III ) and has a bimetallic ring possessing similar coordination environments for both of the Zn^II cations. Although complex ( II ) also contains a bimetallic ring, the two Zn^II cations have different coordination environments. Under the influence of the I^? anion and guest CHCl₃ molecule, complex ( IV ) displays a significantly different structure with respect to complexes ( I )–( III ). C—H…Cl and C—H…N hydrogen bonds, and π–π stacking or C—Cl…π interactions exist in complexes ( I )–( IV ), and these weak interactions play an important role in the three‐dimensional structures of ( I )–( IV ) in the solid state. In addition, the fluorescence properties of L and complexes ( I )–( IV ) were investigated.     

Racemic and chiral 1‐[N‐(chloro­acetyl)carbamoylamino]‐2,3‐dihydro‐1H‐inden‐2‐yl chloroacetate

In the racemic crystals of (1S,2R)‐ or (1R,2S)‐1‐[N‐(chloro­acetyl)­carbamoyl­amino]‐2,3‐di­hydro‐1H‐inden‐2‐yl chloro­acetate, C₁₄H₁₄Cl₂N₂O₄, (I), the enantiomeric mol­ecules form a dimeric structure via the N—H?O cyclic hydrogen bond of the carbamoyl moieties. In the chiral crystals of (—)‐(1S,2R)‐1‐[N‐(chloro­acetyl)­carbamoyl­amino]‐2,3‐di­hydro‐1H‐inden‐2‐yl chloro­acetate, C₁₄H₁₄Cl₂N₂O₄, (II), the N—­H?O intermolecular hydrogen bond forms a zigzag chain around the twofold screw axis. The melting points and calculated densities of (I) and (II) are 446 and 396 K, and 1.481 and 1.445 Mg m^?3, respectively.     

Structural diversity in imidazolidinone organocatalysts: a synchrotron and computational study

(S)‐1‐(Methylaminocarbonyl)‐3‐phenylpropanaminium chloride (S2·HCl), C₁₀H₁₅N₂O⁺·Cl⁻, crystallizes in the orthorhombic space group P2₁2₁2₁ with a single formula unit per asymmetric unit. (5R/S)‐5‐Benzyl‐2,2,3‐trimethyl‐4‐oxoimidazolidin‐1‐ium chloride (R3 and S3), C₁₃H₁₉N₂O⁺·Cl⁻, crystallize in the same space group as S2·HCl but contain three symmetry‐independent formula units. (R/S)‐5‐Benzyl‐2,2,3‐trimethyl‐4‐oxoimidazolidin‐1‐ium chloride monohydrate (R4 and S4), C₁₃H₁₉N₂O⁺·Cl⁻·H₂O, crystallize in the space group P2₁ with a single formula unit per asymmetric unit. Calculations at the B3LYP/6–31G(d,p) and B3LYP/6–311G(d,p) levels of the conformational energies of the cation in R3, S3, R4 and S4 indicate that the ideal gas‐phase global energy minimum conformation is not observed in the solid state. Rather, the effects of hydrogen‐bonding and van der Waals interactions in the crystal structure cause the molecules to adopt higher‐energy conformations, which correspond to local minima in the molecular potential energy surface.