The synthesis, structure and some properties of C{sub 2}H{sub 7}N{sub 4}O {center_dot} ZnPO{sub 4} (guanylurea zinc phosphate) are reported. The cationic template was prepared in situ by partial hydrolysis of the neutral 2-cyanoguanidine starting material. The resulting structure contains a new, unprotonated, zincophosphate layer topology as well as unusual N-H-O template-to-template hydrogen bonds which help to stabilize a ''double sandwich'' of templating cations between the inorganic sheets. Crystal data: C{sub 2}H{sub 7}N{sub 4}O {center_dot} ZnPO{sub 4}, M{sub r} = 229.44, monoclinic, P2{sub 1}/c, a = 13.6453 (9) {angstrom}, b = 5.0716 (3) {angstrom}, c = 10.6005 (7) {angstrom}, {beta} = 95.918 (2){sup 0}, V = 729.7 (1) {angstrom}{sup 3}, R(F) = 0.034, wR(F) = 0.034

HARRISON,WILLIAM T.A.

NENOFF,TINA M.

PHILLIPS,MARK L.F.

RODGERS,JENNIFER A.

Harrison, William T. A.

Rodgers, Jennifer A.

Phillips, Mark L. F.

Nenoff, Tina M.

UNT Digital Library

In Situ Template Generation For Zincophosphate SynthesisLeading to C2H7N40*ZnP04 ContainingTemplate-to-template N–H”-”OHydrogen BondsWilliam T. A. Harrison,$’* Jennifer A. Rodgers,$Mark L. F. Phillips,$ and Tina M. Nenof~‘Department of Chemistry,University of Aberdeen,Aberdeen, AB243UE, UKe-mail w.harrison@abdn. ac.ulc‘27468 Hayward Boulevard,Hayward, CA 94542, USA‘Environmental Monitoring and Characterization,PO Box 5800, MS 0755, Sandia National Laboratories,Albuquerque, NM 87185-0755, USASubmitted to ht. J Inorg. Mater.JDISCLAIMERThis report was prepared as an account of work sponsoredby an agency of the United States Government. Neitherthe United States Government nor any agency thereof, norany of their employees, make any warranty, express orimplied, or assumes any legal liability or responsibility forthe accuracy, completeness, or usefulness of anyinformation, apparatus, product, or process disclosed, orrepresents that its use would not infringe privately ownedrights. Reference herein to any specific commercialproduct, process, or service by trade name, trademark,manufacturer, or otherwise does not necessarily constituteor imply its endorsement, recommendation, or favoring bythe United States Government or any agency thereof. Theviews and opinions of authors expressed herein do notnecessarily state or reflect those of the United StatesGovernment or any agency thereof.PortionsDISCLAIMERof this document may be illegiblein electronic image products. Images areproduced from the best available originaldocument.‘\AbstractThe synthesis, structure and some properties of CzHTNqO”ZnPOo (guanylurea zinc phosphate)are reported. The cationic template was prepared in situ by partial hydrolysis of the neutral 2-cyanoguanidine starting material. The resulting structure contains a new, unprotonated,zincophosphate layer topology as well as unusual N–H-O template-to-template hydrogenbonds which help to stabilise a “double sandwich” of templating cations between theinorganic sheets. Crystal data: CQHTNoO”Zd?Oo,M, = 229.44, monoclinic, P21/c, a = 13.6453(9) & b = 5.0716 (3)&C= 10.6005 (7)&~= 95.918 (2)0, V = 729.7 (1) ~’, R(F) = 0.034,WR(F) = 0.034.‘IntroductionOrganically-templated zincophosphate frameworks (ZnPOs) built up from vertex-linkedZn04 and P04 tetrahedral show considerable structural diversity with some 30 examples .characterised so far. 1 In an ex pst~acto sense, a particular ZnPO structure can be correlatedwith the conformation and H-bonding properties of the organic species.2 For ZnPOs this isinvariably a cation (usually a protonated amine), and template-to-framework N–H-””Ointeractions are assumed to have a strong structure-directing effect.3 However, structureprediction for a particular set of starting materials, based on the ideas of crystal engineeringvia H bonding networks,4 remains an elusive concept, although some trends are beginning tobecome more apparent.5Here, we report the solution-mediated synthesis, single-crystal structure, and someproperties of guanylurea (2) zinc phosphate, CzHTNQO”ZnPOo. The cationic template wasprepared by the slow, partial hydrolysis of neutral 2-cyanoguanidine (l). As expected, theneutral molecule 1 has no templating- effect for ZnPOs, although it strongly interacts withzincophosphite (Zn–HP03) networks by way of Zn–N bonds.G[scheme 1 near here]Experimental SectionSynthesis: 2.52 g (30 mmol) CzNq~ (2-cyanoguanidine, Aldrich), 0.81 g (10 mmol) ZnO(Spectrum), 1.70 g (20 mmol) HqP03, 97’XO(Aesar), and 18.0 g (1 mol) deionized water were‘Lcombined in a HDPE bottle. This was shaken well and placed in a 70 “C oven for 3 days,after which the contents were filtered hot. The pH of the mother liquors was 5. The solidproduct was washed with water, then methanol, and dried at 70 ‘C. The yield was xxx (xx’?40based on Zn) of transparent plates and needles of the title compound. An X-ray powderpattern indicated phase purity and high crystallinity.CUW1 structure determination: A transparent rod of CzHTN@”ZflOQ, dimensions -0.05 X0.06 x 0.43 mm, was mounted on a Bruker _SMART 1000 CCD diffractometer (Mo Karadiation, A = 0.71073 ~).7 Frames were collected in narrow-slice co-scan mode for 2°< 2e <65°. An empirical absorption correction (correction factor range= 0.569–0.802) was appliedwith SADABS, resulting in 7305 scanned reflections. After merging to 2575 unique data (l?Int= 0.019), 2222 reflections were considered observed with 1> G(1). The starting atomicparameters were established by direct methods,* and full-matrix least-squares refinement wascarried out with CRYSTALS9 (calculated weighting scheme’”). All the H atoms were locatedfrom difference maps and their positional and isotropic thermal factors were refined withoutconstraints. Crystallographic parameters are summarised in Table 1!IResults and DiscussionThe CryStal structure (Figure 1 and 2) of CzHTN@”ZfloQ is built up from aherna~inginorganic and organic layers. Selected geometrical data are presented in Table 2. The anionic[ZnPOQ]- sheets, which propagate normal to [100], are built up from vertex-sharing Zn04 andP04 tetrahedral. The Znl species [daV(Zn–O) = 1.953 (2) ~] makes two Zn–O–P bonds (via01 and 03) and two Zn-02-(P,Zn’) links. The trigonal coordination of 02 results in infinite,contorted chains of Zn04 tetrahedral propagating along [010]. The P 1 species [d,,(P–O) =1.541 (2) ~] makes two P–O–Zn bonds, one P–02–(Zn,Zn’) link, and a short, terminal P–04vertex. This short bond [d = 1.515 (2) ~] indicates that it is not protonated. 11 The linkagepattern of the tetrahedral leads to sheets of edge-sharing 3- and 4-ring loops (Figure 3). Webelieve that CzH7N40.ZnP04 is the first layered ZnPO to contain such an unprotonatedtetrahedral sheet.The essentially flat conformation (maximum atomic deviation from the best least-squares plane <0.13 ~) of the organic cation is similar to that of the same species in simplesalts .12 The template cations arrange into distinctive double layers between the inorganicsheets (Figure 2). Thus, the topological connectivity is sheet”. ”template.”template”-sheet,rather than the more commonly seen sheet template””-sheet configuration. Hydrogen bonding(Table 1) appears toinvolved in hydrogenbe a key factor in stabilizing this structure. All seven H atoms arebonds of varying strength (two of which are bifurcated), with d(W-”O)ranging from 1.98 (5) to 2.42 (5) & based on the freely refined H atom positions. As well asthe typical N–H.”Of (template-to-framework) interactions,l-3 novel N i–Hi “.”O 5t (inter-molecular template-to-template) linkages are present. This linkage” serves to “dimerise” twotemplate molecules about an inversion centre (Figure 4). There is also an infra-molecularN3–H5.”05 interaction (Figure 1). The terminal 04 atom of the ZnPO sheet is the acceptorspecies for no fewer than four H bonds.In summary, guanylurea zinc phosphate, C2.HTNqO-Z~ol, displays two unusualaspects of open-fi-amework ZnPO chemistry:● in situ generation of a cationic template from a neutral starting material, and<. template-to-template N–H”””O hydrogen bonds due to the strong H-bond accepting C=Ogroup of the template molecule.This second point suggests that templates containing strong H-bond acceptors as well as Hbond donors (protonated amide groups) can play a distinctive structure-directing role fortemplated structures and that the ideas of crystal engineering could be fruitfully applied tothis area.Acknowledgements: This work is supported by the US Department of Energy under contractDE-AC04-94AL85000. Sandia is a multi-program laboratory operated by SandiaCorporation, a Lockheed Martin Company, for the US Department of Energy.<,References(1) W. Liu, Y. Liu, Z. Shi, and W. Pang, J. Mater. Chem., 2000, 10, 1451, and includedreferences.(2) W. T. A. Harrison and M. L. F. Phillips, Chem. Mater. 1997,9,1837.(3) D. Chidambaram, S. Neeraj, S. Natarajan, and C. N. R. Rae, JSolid State Chem. 1999,147, 154.(4) For example: A. B. Koren; M. D. Curtis, and J. W. Kampf, Chem. Mater., 2000,12,1519,and included references.(5) S. Neeraj, S. Natarajan, and C. N. R. Rae, ~ Solid State Clzenz., 2000,150,417.(6) W. T. A. Harrison, M. L. F. Phillips, J. Stanchfield, and T. M. Nenoff, hzorg. Chem.,2001, submitted for publication.(7) SMART, SAINT and SADABS software for area-detector diffractometers, BrukerAnalytical X-ray Systems, Madison, Wisconsin, USA (1999).(8) G. M. Sheldrick, SHELXS-86 User Guide, University of Gottingen, Germany (1986).(9) J. R. Carruthers, D. J. Watkin, and-P. W. Betteridge, CRYSTALS User Guide, Universityof Oxford, UK (1999).(10) J. R. Carruthers and D. J. Watkin, Acts Cry.stallogr. 1979, A35, 698.(11) P. Lightfoot and D. Masson, Acts Crystallogr. 1996, C52, 1077.(12) N. Zaman and F. S. Darlow, J Bangladesh Acad Sci., 1986,10,79.‘,Figure CaptionsFigure 1. Fragment of the CzHTNqO.ZnPOo structure (50% thermal ellipsoids, spheres ofarbitrary radius for H) showing the atom labelling scheme. Hydrogen bonds are indicated bydotted lines and symmetry generated atoms are indicated by Ola, etc.Figure 2. The structure of CzHTNoo”Z?.&OL$viewed down [010], with the ZnPO layerrepresented by polyhedra (Zn04 dark shading, P04 light shading).Figure 3. Detail of the CzHTNoO”Zd?().4 structure viewed approximately down [100] showingthe tetrahedral connectivity in an infinite [ZnP04]- sheet.Figure 4. Detail of the CzHTN@”Zd?Oo structure showing a dimerised pair of templatemolecules.IITable 1: Crystallographic Parameters for C2H7N40”ZnP04Empirical formulaM,Crystal system ,Space groupa (~)b@)c (A)P (0)v (A3)zTA (A)P.,IC(#cm3)p (cm-l)min., max. Ap (e /~3)R(F)qwR(F)b‘..c2H7NL@”hp@263.48monoclinicP2*/c (NO. 14)13.6453 (9)5.0716 (3)10.6005 (7)95.918 (2)729.7 (1)4298 (2) K0.710732.398”35.84–0.60, +0.800.0340.034‘R=ZI IFOI-IFCI I/ ZIFOIbRw=[xw (l Fol–l Fcl)2/xwl Fo12]1’2I‘.Table 2: Selected Bond Distances(&a/Angles~) for CzH7N40”ZnP04Znl-01 1.917 (2)Znl-02 1.9953(19)P1-ol 1.525(2)P1-03 1.542(2)05–C1 1.240(3)C1-N2 1.395(4)c2-N3 1.320(4)Znl-01-Pl 134.20(1,3Znl-02-Pl 128.37(11Znl-03-Pl 128.46(12Znl-02 1.9789(19)Znl-03 1.920(2)P1-02 1.5802(19)P1–04 1.515(2)C1-N1 1.335(4)C2-N2 1.358(4)C2–N4 1.315(4)Znl-02-Znl 118.69(9)Znl-02-Pl 112.9(1)N1-H1...O5N1-H2...O4N2-H3...O4N2-H3...O3N3-H4...O4N3-H5...O5N4–H6...O4N4–H7...O1N4–H7...O30.84(4)0.86(5)0.89(4)0.89(4)0.87(5)0.83(4)0.91(5)0.96(6)0.96(6)2.18(4) 3.014(4)1.98(5) 2.802(3)2.12(4) 2.925(4)2.34(4) 3.031(3)2.42(5) 3.155(4)2.12(4) 2.729(4)2.03(5) 2.900(4)2.29(6) 3.088(4)2.38(5) 3.125(4)171(4)159(5)150(4)135(4)142(4)130(4)158 (4)140(4)134 (4)IaForthehydrogen bonds, the fourvalues refertotheN–H, H--O,andN””Ose parations, andtheN–H-Obond angle, respectively.‘Figure 1HICl(_)$CHaH4 N4 H7WI6H6Figure 2‘.Figure 3<, ,Figure 4

In Situ Template Generation for Zincophosphate Synthesis Leading to C2H7N4O-ZnPO4 Containing Template-to-Template N--H...O Hydrogen Bonds

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In Situ Template Generation for Zincophosphate Synthesis Leading to C2H7N4O-ZnPO4 Containing Template-to-Template N--H...O Hydrogen Bonds

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