摘要:

Dario BragaDario Braga is Professor of Chemistry at the University of Bologna. He received the Raffaello Nasini Prize from the Italian Society of Chemistry in 1988 for his studies on solid state dynamic processes, and the FEDERCHIMICA Prize in 1995 for his research on the intermolecular interactions in organometallic systems. Presently, his main scientific interests are in the crystal engineering exploitation of hydrogen bonding interaction between ions, in the investigation of crystal polymorphism and in solvent-free gas–solid and solid–solid reactions. He has published more than 300 papers and reviews and organized several international conferences and schools on crystal engineering. Dario Braga is the Master of the Collegio Superiore of the University of Bologna. He is member of the international editorial board of Chemical Communications and the Scientific Editor of CrystEngComm.

ISSN:1466-8033    

DOI:10.1039/b417413e

出版商:RSC    

年代:2004

数据来源: RSC

摘要:

The Editorial Board and Editorial Office are delighted to announce the first impact factor forCrystEngComm– 2.730! We have been working to bring you a journal that provides high impact, good quality science, since the journal's launch in 1999. The impact factor (produced by ISI) published in June 2004 verifies just this. Of course, without your support, the journal would not have achieved this excellent result. We extend the thanks of the Editorial Board and Editorial Office to allCrystEngCommauthors who have published in the journal and all referees who have helped select the best work, which has helped us to achieve this impressive first impact factor.We also aim to offer the fastest publication times in the crystal engineering community forCrystEngCommauthors. Currently, the typical time from receipt of the article in the Editorial Office to final publication inCrystEngCommis just 50 days (one Full Paper has been published in 2004 in just 10 days!).CrystEngCommalso serves the community through the publication ofCrystEngCommHighlights, the latest beingCH/π hydrogen bonds in crystalsby Motohiro Nishio (CrystEngComm, 2004,6, 130).We encourage you all to be part of the success ofCrystEngComm, and to take advantage ofCrystEngComm's excellent publication times, free use of colour, electronic enhancements and high impact. Full Papers, Communications and Letters can be submitted to the Editorial Office onlineviawww.rsc.org/submissions.September 2004 sees the secondCrystEngCommDiscussion meeting,New Trends in Crystal Engineering, to be held in Nottingham, UK (8–10 September). Details athttp://www.rsc.org/lap/confs/cecd2004.htm. This meeting will build on the strengths and success of the first Discussion meeting held in 2002, and will bring together an international cross-section of researchers from all areas of crystal engineering. It is not too late to submit an abstract for the poster session. Don't miss out, ensure that your poster can be presented at the meeting, and contact the conference office (conferences@rsc.org) without delayCrystEngCommin September.Professor Dario Braga, Scientific EditorDr Lee Brammer, Chair, Editorial BoardDr Jamie Humphrey, Managing Editor

ISSN:1466-8033    

DOI:10.1039/b410708j

出版商:RSC    

年代:2004

数据来源: RSC

摘要:

IntroductionThe alicyclic diols1–4illustrated inFig. 1are examples of the helical tubuland inclusion host family.1–4These compounds are noteworthy for forming a chiral hydrogen bonded network structure in space groupP3121 (or its enantiomorphP3221) that contains parallel guest-filled tubes. Spontaneous self-resolution5,6of the racemic diol occurs during crystallisation to yield a mixture of pure (+)- and pure (−)- helical tubulate inclusion crystals.7The supramolecular motif8dominating these assemblies is an infinite spiral of hydrogen bonded diol hydroxy groups ⋯O–H⋯O–H⋯O–H⋯ that form a spine-like structure surrounding a threefold screw axis. When viewed along the spine axis, the diol molecules are observed as three eclipsed stacks and the hydrogen bonding as a triangular projection.Molecular structures of the alicyclic diols1–4, typical members of the helical tubuland host family. Only one enantiomer of each chiral compound is illustrated.Twelve helical tubuland diols, each with a different tube size and cross-section, have been prepared so far. Guest molecules are generally included within the tubes on a size and shape, rather than functional group, basis.Formation of a helical tubulate inclusion compound depends entirely on the hydrogen bonded spine being formed during crystallisation, so the use of polar or hydrogen bonding solvents introduces the very real possibility that alternative motifs may be formed on a competitive basis. Water2,9and phenols2,10,11are not included as guest molecules in helical tubulate compounds but, for some helical tubuland diols only, they yield hydrogen bonded co-crystalline adducts instead. Hence, we are currently exploring the likelihood of other polar or protic solvents yielding co-crystalline products with known helical tubuland diols.Remarkably, diol1forms helical tubulate compounds with guests such as chloroacetic acid, ethanol, diethyl amine, nitromethane, and dimethyl sulfoxide.1Non-polar, polar, and protic guests are all included within its tubular cavities, and no co-crystalline adducts have been observed12(other than a few phenols).10The helical tubulate, (1)3·(propanoic acid)1.2, is a good example of this behaviour and is shown inFig. 2(where only one guest disorder component is illustrated). Propanoic acid has excellent hydrogen bonding potential but, nonetheless, is included as a series of self-dimers within the tubes of the diol host.1Projection view in theabplane of five adjacent tubes of the helical tubulate compound (1)3·(propanoic acid)1.2. Atom code: host C green, O red, H light blue, and guest C purple. The dominant supramolecular motif is an infinite spiral of hydrogen bonded diol hydroxy groups ⋯O–H⋯O–H⋯O–H⋯ that form a spine-like structure surrounding a threefold screw axis. Hydrogen bonds are shown as red lines. Viewed down the spine axisc, the diol molecules are observed here as three eclipsed stacks and the hydrogen bonding as a triangular projection. For clarity, only one propanoic acid guest (with its acidic hydrogen atom omitted) is shown in each host tube.Recently, however, we have discovered that helical tubuland diol–alcohol adducts are occasionally produced. For example, diol2yields a 1 ∶ 1 adduct with ethanol.13The major supramolecular motif8in this structure is a hydrogen bonded (O–H)6cycle.14–16Four molecules of2and two molecules of ethanol contribute a hydroxy group to each of these centrosymmetric rings.In contrast, the compound (3)·(methanol) has a very different overall co-crystalline structure. It retains the infinite spiral hydrogen bonded spines of the helical tubuland lattice, but the repeating sequence of contributing hydroxy groups is now ⋯diol O–H⋯methanol O–H⋯diol O–H⋯. Thus, the hydrogen bonded ⋯OH⋯OH⋯OH⋯ sequence now surrounds a pseudo-threefold screw axis, and one of the three stacks of diol molecules subtended from each spine has been replaced by a stack of methanol molecules.11Here we report on the behaviour of4when crystallised from protic organic solvents. This particular diol is unusual in forming helical tubulate compounds with relatively large guest molecules, but ellipsoidal clathrate compounds with smaller ones.2The latter arrangement is a complex structure involving interpenetration of two identical, but inversion related, sub-lattices.9,17,18Each sub-lattice is hydrogen bonded and contains both diol enantiomers. The guest molecules occupy small ellipsoidal shaped voids present between the two sub-lattices.

ISSN:1466-8033    

DOI:10.1039/b313956e

出版商:RSC    

年代:2003

数据来源: RSC

摘要:

IntroductionWe are investigating the crystal supramolecular chemistry of combinations of arylated cations and polyiodide anions. These systems are comprised of three general types of intermolecular interaction: (a) concerted multiple aryl embraces, (b) the associations of high-Zatoms for which there is substantial stabilisation, due to dispersion, and (c) aryl⋯polyiodide interactions in several geometries, including (aryl-edge)C–H⋯I and I⋯aryl-face. Polyiodides, studied over a long period in numerous compounds,1–3manifest a structural diversity which is due to the fact that in them intermolecular energies are not very different from intramolecular energies, and the potential energy surfaces are flat.4–6In the context of the supramolecular chemistry of inorganic molecules containing high-Zatoms, polyiodides provide an informativeextreme, which is the reason for our continuing investigation of them. One characteristic of the class of crystalline polyiodides with arylated cations is the general absence of conventional protic hydrogen bonding as a supramolecular motif, and therefore the relative influences of the interaction types (a), (b) and (c) can be investigated and assessed. Polymorphism, or crystal packing isomerism,7,8is prevalent amongst polyiodides, and its occurrence reflects the similar magnitudes of the interaction energies and the relative flatness of the interaction potentials.We have generated 14 different crystals that contain the [Fe(phen)3]2+cation (phen = 1,10-phenanthroline) associated with polyiodides of variable stoichiometry, as [Fe(phen)3]Ixwherex= 4, 6, 7, 8, 12, 14 and 18.9–13Cations of the type [M(phen)3]2+manifest characteristic supramolecular motifs with themselves, comprised of offset-face-to-face (OFF) and edge-to-face (EF) interactions between phen ligands: these well-established motifs, known as embraces, provide net energy stability between cations.14Throughout the series [Fe(phen)3]Ixwith increasing iodine content there is a structural progression in which the embraces between [Fe(phen)3]2+cations14are increasingly restricted, until in [Fe(phen)3]I18the [Fe(phen)3]2+cations are separated from each other in an iodinous matrix.13[M(phen)3]2+complexes and polyiodides demonstrate a complementary geometrical orthogonality, in which Ixchains occupy the inter-phen grooves, and engage C–H⋯I interactions around the perimeters of the phen ligands.12During these investigations we uncovered six different crystalline combinations of [Fe(phen)3]2+with the simplest polyiodide, I3−. These crystals all contain some solvent, and so can be classified as pseudo-polymorphs.15We describe and discuss five of these crystal structures in this paper. Previously we described and analysed the dimorphs of [Cu(phen)2I]I316and the trimorphs of [Fe(phen)3]I12.10The crystals considered in this paper are:[Fe(phen)3]I6·CH2Cl21-CH2Cl2[Fe(phen)3]I6·(acetone)0.51-acetone[Fe(phen)3]I6·CH3CN2-CH3CN[Fe(phen)3]I6·toluene3-toluene[Fe(phen)3]I6·H2O4-H2O.There are four distinct crystal lattices, indicated by the four numerals.

ISSN:1466-8033    

DOI:10.1039/b109311h

出版商:RSC    

年代:2001

数据来源: RSC

摘要:

I am very pleased and excited to announce in this Editorial the publication of issues inCrystEngComm. This change to the way in which articles in the journal are published will mean that readers of the journal will find it simpler to find articles in the journal, as the format will be similar to the online versions of print journals.CrystEngCommarticles will be published in HTML and PDF monthly, in issues, starting with this issue. Communications will be collected together at the beginning of the issue, followed by Full Papers, and the issues will be announced with monthly email alerts. This move to publication of electronic issues reflects the growing strength of the journal, and the increase of the articles (Communications and Full Papers) submitted for publication. We have seen an increase of 40% from 2005 compared to 2004. Articles inCrystEngCommwill appear online first as Advance Articles, before being assigned to issues.In 2005,CrystEngCommretained its number one position as the fastest journal for the publication of crystal engineering with a typical publication time (from receipt to publication) of 65 days for full papers, and 40 days for communications. The Editorial Office and Editorial Board remain committed to publishing the highest quality research in the fastest times.Retiring members of the Editorial Board Professors Phil Coppens, Juerg Hulliger and Sally Price, and Advisory Board members Professors Harris, Boese, Foxman, Fujita and Mann are thanked for their efforts to develop the journal during the past few years, as well as providing support for the journal. We welcome to the Editorial Office in Cambridge Dr Ian Gray and Dr Niamh O'Connor to theCrystEngCommEditorial Team. Ian has recently joined us as part of the RSC Graduate Trainee scheme, after completing a PhD in main group chemistry. Niamh O'Connor joins the team in the role of Deputy Editor, after spending a year with the RSC working in the Analytical Abstracts Production department. Niamh holds a PhD in organometallic chemistry.The 2004 impact factors, released by ISI© in June 2005, showed an impressive average increase of over 10% for RSC journals. The impact factor forCrystEngCommwas published as 2.585. Calculated annually, ISI impact factors provide an indication of the quality of a journal—they take into account the number of citations in a given year for all the citable documents published within a journal to the preceding two years. It is worth noting that alongside the ACS publications, journals from RSC Publishing have the highest median impact factor among publishers in the chemical sciences. This encouraging statistic demonstrates the recognition and status that researchers place in society published work.2005 has seen RSC Publishing invest significantly in technological developments across all of its products. First there was the introduction of the new website in the summer which included a contemporary, fresh look and an enhanced structure for improved and intuitive navigation between relevant, associated content. The improvements to the technological infrastructure have made the site more flexible and efficient, and better equip the RSC to deliver enhanced publishing products and services for its customers in the future. The new look was just the start and towards the end of the year we were pleased to provide further enhancements in the form of RSS feeds and ‘forward linking’ facilities.RSS, or ‘really simple syndication’, is the latest way to keep up with the research published by the RSC. The new service provides subscribers with alerts as soon as an Advance Article is published in their journal of choice. Journal readers simply need to go to the journal homepage, click on the RSS link, and follow the step-by-step instructions to register for these enhanced alerts. RSS feeds include both the graphical abstract and text from a journal's contents page—i.e.they deliver access to new research straight to a reader’s PC, as soon as it is published! Many feed reader software packages also have the added benefit of remembering what has been read previously, which in turn makes tracking and managing journal browsing more efficient. ‘Forward linking’, the reverse of reference linking, enables readers to link from any RSC published paper to the articles in which it is cited. In essence, it allows researchers to easily track the progression of a concept or discovery since its original publication. With one click of a button (on the ‘search for citing articles’ link) a list of citing articles included in Cross-Ref is presented, complete with DOI links.At a time when research is becoming increasingly interdisciplinary in nature and the amount of published works continues to grow, it is hoped that the new technology, developed in conjunction with Cross-Ref, will significantly reduce the time spent by researchers searching for information.These developments demonstrate the investment in publishing products and services over the past year and 2006 will see us enhancing our products further, with improvements to the HTML functionality of all journals and ReSourCe (the author and referee web interface) already underway.As well as an impressive portfolio of prestigious journals, the RSC has a significant collection of book titles. The first titles in three new series:RSC Biomolecular Sciences;RSC Nanoscience & Nanotechnology Series; andIssues in Toxicologywere published in 2005, with further titles due during 2006. Future growth in the books publishing programme is planned, which reflects the increasingly interdisciplinary nature of the chemical sciences.I would be delighted to hear your comments onCrystEngComm. Please send any comments to the Editor, Jamie Humphrey (crystengcomm@rsc.org)Have a successful 2006!Dr Jamie Humphrey, Editor

ISSN:1466-8033    

DOI:10.1039/b517671a

出版商:RSC    

年代:2005

数据来源: RSC

摘要:

The construction of transition metal co-ordination polymers is a well established facet of crystal engineering.1–4For several years, effort has been concentrated on the development of bridging ligands of ever-increasing sophistication to link metal centres and hence generate multi-dimensional, multi-functional architectures.1–5More recently the use of supramolecular synthons based on π–π stacking6and hydrogen-bonding7–10interactions has been developed, leading to a new era of network materials. The linking of transition metal cationic centres through anionsviahydrogen-bonded supramolecular synthons to fabricate new extended structures is a topic in which we are particularly interested as it brings together the complementary fields of hydrogen-bonded crystal engineering11,12and inorganic co-ordination polymer construction.1–5In a recent paper,8we reported the formation of a hydrogen-bonded rhombic (4,4) grid based on a combination of the bis(N-methylamidino-O-methylurea)copper(ii) cation, a planar four-fold connecting unit, with the chloride anion, [Cu(Lmm)2]·2Cl (MMCL). The four-fold connectivity of the cation arises from the presence of four pairs of N–H donors disposed at 90° intervals as shown inScheme 1. Two pairs of N–H donors are associated with non-co-ordinated nitrogen atoms (those hydrogen-bonded to X inScheme 1) while the other two pairs are associated with co-ordinated nitrogen atoms (those hydrogen-bonded to Y inScheme 1). The rhombic (4,4) grid results from the use of all four pairs of N–H donors to form hydrogen bonds to four symmetry-related chloride anions. The hydrogen-bonding assemblies linking cations and halide anions adopt R12(6) motifs as shown inScheme 1.Schematic representation of the [CuL2]2+cation showing the disposition of the four pairs of N–H donors and the formation of R12(6) motifs.A reassessment of earlier work13,14involving bis(amidino-O-ethylurea)copper(ii) cations and halide anions has revealed similar (4,4) grids. In the bromide, [Cu(LHe)2]·2Br (HEBR),13the cations are linked solely by halide anions as in [Cu(Lmm)2]·2Cl; in the chloride, [Cu(LHe)2]·2Cl·2H2O (HECL),14however, both halide anions and water molecules are involved in the hydrogen-bonding interactions.To investigate the prevalence of (4,4) grid formation we have synthesised and structurally characterised a range of compounds analogous to [Cu(Lmm)2]·2Cl and differing solely in alkyl substituents and anion. Thus, a total of ten compounds of diverse bis(N-alkylamidino-O-alkylurea)copper(ii) cations with chloride and bromide have been synthesised, of which six have been structurally characterised by single crystal X-ray diffraction methods. The cations are synthesised by solvolysis ofN-alkyl-2-cyanoguanidines, prepared by reaction of an alkylamine hydrochloride with sodium dicyanamide in butan-1-ol in the presence of a copper(ii) salt as shown inScheme 2. Consequently, by variation of alkylamine hydrochloride (MeNH2·HCl, EtNH2·HCl or PhCH2NH2·HCl), solvent (MeOH or EtOH) and copper(ii) salt (CuCl2·2H2O or CuBr2) a diverse range of complexes has been prepared.Synthetic route to the [CuL2]·2X hydrogen-bonded co-ordination complexes.

ISSN:1466-8033    

DOI:10.1039/b210185h

出版商:RSC    

年代:2002

数据来源: RSC

摘要:

James ChisholmJames Chisholm received an M.Sci. in theoretical physics from the University of St. Andrews, Scotland in 1996 and a Ph.D. in materials science from the University of Cambridge in 2000. Since 2002 he has been a Scientific Software Engineer at the CCDC, having previously worked as a computer consultant for Tessella Support Services. James' interests lie in the development of efficient software for the search and analysis of crystal structures.

ISSN:1466-8033    

DOI:10.1039/b516891k

出版商:RSC    

年代:2005

数据来源: RSC

摘要:

CrystEngCommcontinues to grow from strength to strength. The successful launch of monthly issues in 2006 was a significant, and very popular, development for the journal. Alongside the monthly issues, the journal now features cover images (see the Cover Gallery athttp://www.rsc.org/Publishing/Journals/ce/Gallery.aspandFig. 1for some examples).Some eyecatching covers appearing onCrystEngCommin 2006.The 2005 impact factors, released by ISI®in June 2006, showed an impressive average increase of over 10% for RSC Journals. We were delighted to see that the impact factor forCrystEngCommincreased by 35%, to 3.508, the highest impact factor the journal has ever had. At the same time, the journal's immediacy index increased by over 50%, to 0.723, showing that the science published in the journal is amongst the most topical! These impressive new figures reinforce the RSC's reputation as the home of exciting new research. Calculated annually, ISI®impact factors provide an indication of the quality of a journal—they take into account the number of citations in a given year for all the citable documents published within a journal in the preceding two years. The immediacy index measures how topical and urgent papers published in a journal are, by dividing the number of citations in a given year by the number of articles published in the journal that year.After many years at the helm of the journal, we say good bye to Professor Dario Braga as Scientific Editor of the journal. Dario played a fundamental part on the launch of the journal in 1999, and since that time has continued to provide his advice and guidance to the journal with his typical enthusiasm! We also bid a fond farewell to Professor Lee Brammer, whose term of office as Chair of the Editorial Board ends at the end of 2006. Lee has helped to oversee the transition of the journal from a new start-up journal to a more established journal.We are delighted to announce that Neil Champness (Nottingham, UK) will become Chair of the Editorial Board from January 2007. Neil has been a member of the Editorial Board since 2002, and has a very good understanding of the journal, and crystal engineering community which the journal aims to serve. We wish him well in his new role as Chair of theCrystEngCommEditorial Board.We thank retiring members of the Advisory Board, Professors Dance, Schroder, Hosseini and Toda for their efforts to develop the journal during the past few years, as well as providing support for the journal. We also welcome to the Editorial Office in Cambridge Drs May Copsey and Freya Means. May joins us from the Professor Tristram Chivers group at the University of Calgary, where she worked on metal telluride thin-films, after finishing her PhD studies at Bristol University, UK. Freya completed her PhD studies at the University of New South Wales with Professor Justin Gooding, on the topic of DNA biosensing.

ISSN:1466-8033    

DOI:10.1039/b616744f

出版商:RSC    

年代:2006

数据来源: RSC

摘要:

In 2008 we celebrate the tenth year of publication forCrystEngComm. In October 1999, the first article was published, Solvent provides a trap for the guest-induced formation of 1-D host frameworks based upon supramolecular, deep-cavity resorcin[4]arenes, Leonard R. MacGillivray, Jennifer L. Reid and John A. Ripmeester,CrystEngComm, 1999,1, 1, and with such a great startCrystEngCommwas sure to be the success it has become. The growth of the journal has been impressive, significantly increasing in size over the years (seeFig. 1).Number of pages published inCrystEngComm.The journal has also seen significant growth in its impact factor, with year-on-year increases, and currently has its highest impact factor ever, at 3.729.

ISSN:1466-8033    

DOI:10.1039/b717517p

出版商:RSC    

年代:0

数据来源: RSC

摘要:

With the recent upsurge of interest in network structures, interpenetration has attracted considerable attention.1Although fascinating in its own right, interpenetration can present a problem in attempts to prepare porous materials as it inevitably leads to a reduction in pore size. There is, however, evidence that it can also impart a greater degree of stability to a metal–organic framework structure.2Although many of the interpenetrated structures that have been reported involve metal–organic frameworks, there are also examples involving hydrogen bonded networks.3–6The assembly of solid state structures through hydrogen bonds is an extremely topical area of chemistry.7In one of the best illustrations of crystal engineering, Ward and co-workers have shown that guanidinium cations and sulfonate anions assemble through hydrogen bonds into hexagonal sheets,8,9and by using disulfonates these sheets can be connected into three-dimensional arrays with predictable structures.10–12Guanidinium disulfonates have been used to achieve the shape-selective separation of molecular isomers13and second harmonic generation through the use of polar host frameworks.14We have been interested in introducing substituents onto the guanidinium cation to assess the effect the concomitant loss of hydrogen bond donors has on the supramolecular structure.15–18We found that typicallyN,N-dimethylguanidinium sulfonates form ribbons in the solid state in which cation–anion pairs, connected through a DD–AA interaction (graph set R22(8)) are linked into one-dimensional structures through further hydrogen bonds involving either R24(8) or R44(12) graph sets.In order to determine whether these conclusions extend to disulfonates, we have prepared and obtained crystal structures for the naphthalenedisulfonate compounds [C(NH2)2(NMe2)]2[1,5-C10H6(SO3)2]1Crystal data for1: C8H13N3O3S,M= 231.27, monoclinic, space groupP21/c,a= 11.8517(7),b= 10.8528(7),c= 9.1258(5) Å,β= 111.267(2)°,U= 1093.86(11) Å3,Z= 4,ρcalc= 1.404 g cm–3,µ= 0.288 mm–1,T= 150(2) K. Reflections collected 7222, independent reflections 3028 [Rint= 0.0399]. FinalRindices [I> 2σ(I)]:R1 = 0.0436,wR2 = 0.1078.and [C(NH2)2(NMe2)]2[2,6-C10H6(SO3)2]2Crystal data for2: C8H13N3O3S,M= 231.27, monoclinic, space groupP21/c,a= 7.2870(6),b= 19.4830(12),c= 14.679(2) Å,β= 94.837(5)°,U= 2076.6(4) Å3,Z= 8,ρcalc= 1.479 g cm–3,µ= 0.304 mm–1,T= 170(2) K. Reflections collected 36141, independent reflections 4724 [Rint= 0.1151]. FinalRindices [I> 2σ(I)]:R1 = 0.0517,wR2 = 0.1091.. The structures reveal that neither1nor2contains the anticipated hydrogen-bonded ribbons. Instead,1forms hydrogen-bonded sheets that are interlinked by the naphthalene groups into a three-dimensional array. In contrast, the structure of2contains interpenetrating two- and three-dimensional hydrogen-bonded networks.The asymmetric unit of1contains aN,N-dimethylguanidinium cation and one-half of a 1,5-naphthalenedisulfonate anion, the other half of which is generated by inversion symmetry. The cations and sulfonate groups form cation–anion pairs through the anticipated DD–AA interaction involving the unsubstituted cation face. These pairs are severely twisted, with an angle of 130° between the mean cation plane and the plane of the three sulfonate oxygen atoms. The cation–anion pairs are connected into sheets (Fig. 1a) by hydrogen bonds involving the two remaining NH groups. These sheets are interlinked by the naphthalene groups into a three-dimensional array (Fig. 1b).(a) Hydrogen bonded sheets in the structure of1. (b) Interlinking of the hydrogen-bonded sheets of1by the naphthalene groups into a three-dimensional network.The asymmetric unit of2contains two independent cations and two independent anion halves, the remainder of each being generated by inversion symmetry. There are two independent and structurally distinct, interpenetrating networks present in the crystal structure of2, one based on cations containing C(1) and anions containing S(1), and the other based on cations containing C(4) and anions containing S(2).The cations based on C(1) and sulfonate groups based on S(1) are connected into pairs by two hydrogen bonds involving the unsubstituted cation face, but in contrast to1these involve only one sulfonate oxygen atom, so generate the graph set R12(6). These cation–anion pairs are connected into sheets (Fig. 2a) by hydrogen bonds involving the two remaining NH groups, giving rings described by the graph set R66(20). These sheets are linked into a three-dimensional network through the naphthalene groups, which act as bridges between sulfonates (Fig. 2b). The sulfonate groups, when connected by either the naphthalene linker or O⋯H–N–H⋯O hydrogen bonds, define a 5-connected BN (bnn) network,19though there is distortion from trigonal bipyramidal towards square-pyramidal geometry about each node.(a) Hydrogen-bonded sheets in the structure of2. (b) Interlinking of the hydrogen-bonded sheets of2by the naphthalene groups into a three-dimensional network.The cation based on C(4) and sulfonate group based on S(2) form similar cation–anion pairs that contain the graph set R12(6) in contrast to R22(8), which was observed for1. These cation–anion pairs are interlinked through further N–H⋯O hydrogen bonds to form a one-dimensional network, in which rings described by the graph set R44(16) are present. The naphthalene groups connect these chains into sheets (Fig. 3) in which the sulfonate groups define a 4,4 net.One-dimensional hydrogen bonded chains in2interlinked by the naphthalene groups into a two-dimensional network.The three-dimensional network containing C(1) and S(1) interpenetrates with the two-dimensional network containing C(4) and S(2) as shown inFig. 4. This type of interpenetration is rare, with only a few reported examples involving metal–organic frameworks.20,21Compound2is, we believe, the first example involving strong hydrogen bonds, though interpenetration of a two-dimensional hexagonal network and a three-dimensional α-polonium network, both constructed from C–H⋯O interactions has recently been reported.22The gross structure of2consists of interpenetrated two- and

ISSN:1466-8033    

DOI:10.1039/b712678f

出版商:RSC    

年代:2007

数据来源: RSC