Giant Anomalous Strain between High-Pressure Phases and the

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Giant Anomalous Strain between High-Pressure Phases and the Mesomers of Urea Kinga Roszak and Andrzej Katrusiak* Faculty of Chemistry, Adam Mickiewicz University, Umultowska 89b, 61-614 Poznań, Poland S Supporting Information *

ABSTRACT: At high pressure the urea crystal abruptly collapses in two stages. When transforming from phase I to III at 0.48 GPa, the crystal volume is abruptly compressed by 7.3%. At this transition a huge abrupt linear compression to 65% along a and to 95% along c is partly compensated by an unprecedented abrupt negative linear compression (i.e., expansion) to 148% along b. At another discontinuous transformation, at 2.8 GPa to phase IV, the crystal still displays an abrupt negative linear compression to 106% along c. The intermediate phase III between 0.48 and 2.80 GPa increases the contribution of the zwitterionic mesomeric structure of urea molecules and the formation of weak NH···N bonds has been evidenced in phase III. The formation of phase II, above 373 K and above 0.6 GPa reported by Bridgman, has not been confirmed.

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INTRODUCTION The molecular structure of urea, CH4N2O, carbamide, the common end metabolite of animals, long remained unknown and controversial after it was synthesized in laboratory as the first organic compound of purely mineral substrates “without interventions of a vital force” by Wöhler in 1828.1 Urea was also the first organic crystal studied by X-ray diffraction in 1921 by Becker and Jancke,2,3 and its structure was roughly determined (by describing the position of the molecule and its formula consistent with form C in Figure 1, but without precise

pressure affects the mesomer of urea molecules when crystalline urea transforms to high-pressure phases III and IV. The mesomeric transformations are consistent with the intermolecular interactions significantly changed in intermediate phase III, with the collapsed version of ambient-pressure phase I, and with the interactions in the high-density phase IV. The modified molecular dimensions, of otherwise rigid molecule of urea, illustrate the effects of intermolecular interactions on its electronic structure. The mesomeric changes in urea are induced by the relatively low pressure of a fraction of 1 GPa. Our present results are consistent with the different structures of urea observed in the crystalline phase and those of the isolated molecules.21 The infrared and Raman spectra of urea in the solid phase and in polar solvents implied that the C-NH2 group is planar.22 However, the infrared spectra of the isolated urea and urea-d4 (CD4N2O) molecules in the argon matrix found the C−ND2-inversion transitions at 227 cm−1, associated with a shallow pyramidal C−ND2 group.22 Still, before the elucidation of the crystal structure of ambientpressure urea (phase I) in the 1920s, two high-pressure phases of urea ,were discovered by Bridgman in 1916: phase II above 373 K/0.60 GPa and phase III above 293 K/0.48 GPa.23−25 Much later two other phases were reported at 293 K: phase IV above 2.8 GPa and phase V above 7.8 GPa.26 However, a huge strain associated with the transition to phase III damaged the single crystals, and the structure of high-pressure phases III and IV were determined only recently.27 At 296 K and 0.48 GPa,

Figure 1. Three mesomers contributing to the resonance hybrid of the urea molecule.

atomic coordinates) in 1923 by Mark and Weissenberg.4 Pauling’s explanation5−7 of the molecular dimensions reported by Wyckoff and Corey,8 with the C−O bond longer than expected for a double bond and C−N shorter than a single bond, by the resonance hybrid of the molecular and zwitterionic forms (Figure 1), is generally accepted,9,10 while the somewhat misleading molecular form 1C (Figure 1) continues to be used in most textbooks.11−19 In the crystalline urea the distance between C and N atoms of 1.34 Å is intermediate between well-defined single C(sp2)−N(sp3) (1.47 Å) and double C(sp2)N(sp2) (1.26 Å) bonds.20 Here we show that high © XXXX American Chemical Society

Received: November 14, 2016 Revised: December 9, 2016 Published: December 12, 2016 A

DOI: 10.1021/acs.jpcc.6b11454 J. Phys. Chem. C XXXX, XXX, XXX−XXX

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The Journal of Physical Chemistry C phase I collapses to phase III, where every fourth NH···O bond is broken and above 2.8 GPa phase III collapses again to phase IV, where the network of NH···O bond of phase I is recovered. Thus, the phase IV is a collapsed version of phase I and the occurrence of the intermediate phase III remains puzzling. Moreover, until this date there is no information about Bridgman’s phase II. Hence, the continuation of our study on urea, aimed at gathering more precise information about the structural transitions between phases I, II, III, and IV. The ambient pressure tetragonal structure of urea, phase I is wellknown for their NH···O bonded molecules enclosing channel voids. Small voids are also present in the structure of hexagonal ice Ih. There are also other analogueies: both C(NH2)2O and H2O do not undergo solid-state transformations at ambient pressure28−33 and they are prone to form cocrystals.34−40 High pressure phases of urea23−25 and of ice involve the collapse of voids. Recently an analogous group of sugar crystals, with structures dominated by hydrogen bonds OH···O, stable in the low temperature but collapsing at high pressure, was reported.41−43 It was established27 that the transition between phases I and III of the urea crystals induces the strongest strain ever reported, when an abrupt anomalous negative linear compression expands the crystal to 148% of its initial length. Therefore, it was essential to establish if this exceptional deformation of the crystal proceeds stepwise or if pretransition changes reduce this stepwise effect. In this study we also have attempted to determine the unknown structure of phase II, according to Bridgman stable above 373 K and above 0.60 GPa.23−25 The structure of the elusive phase II could provide valuable information about properties of urea. Furthermore, we intended to check if it is possible to obtain a urea hydrate in the high-pressure conditions. It was shown recently that pressure can efficiently change the crystallization preference for the solvatation of thiourea44 and 1,4-diazabicyclo[2.2.2]octane (dabco) salts,45−47 and we wanted to test this approach for urea. Presently more than 199 urea cocrystals and cocrystals hydrates are deposited in the Cambridge Structural Detabase (version 5.37, released in November 2015;20 ConQuest, version 1.1848). However, no hydrate of urea has been reported so far.

Figure 2. Four stages of a urea single-crystal isochoric growth in phase III: (a) a thin plate at 343 K, (b) 333 K, (c) 323 K, and (d) 1.00 GPa/296 K. Four ruby chips were used for pressure calibration group at the left side of the DAC chamber.

Table 1. Selected High-Pressure Crystal Data of Urea Polymorphs I, III, and IV polymorph pressure (GPa) crystal system space group unit cell dimensions (Å)

V (Å3) Dx (g cm−3) Z/Z′

a b c

I 0.15(2) tetragonal P4̅21m 5.638(4) 5.638(4) 4.714(3) 149.8(2) 1.331 2/0.25

III 2.75(2) orthorhombic P212121 3.420(1) 8.145(3) 8.758(4) 243.97(16) 1.635 4/1

IV 2.96(2) orthorhombic P21212 3.408(3) 7.363(8) 4.648(10) 116.7(3) 1.710 2/0.5

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EXPERIMENTAL SECTION High-pressure crystallizations of urea were performed in situ in isothermal and isochoric conditions in a Merrill-Bassett diamond-anvil cell (DAC),49 modified by mounting the anvils directly on steel backing plates with conical windows.50 Powder-diffraction patterns were recorded for the frozen urea:water mixtures (1:1, 1:2, and 1:3 vol.) at 296 K by increasing pressure to 1 GPa on a Xcalibur Diffractometer, equipped with an EOS-CCD detector and an 0.3 mm collimator, and the diffraction images were recorded for the sample rotated about the ω axis at the χ 0, 30, 60 and 90° positions. Diamonds reflections were erased from the imagines, the signal of empty cell was subtracted and the residue intensity was integrated at constant 2θ angles. In all the patterns only the reflections of priscine urea and above 1 GPa also additional reflections of ice VI were found. Apart from the high-pressure studies we attempted to obtain a urea hydrate by isobaric crystallization of 50:50 and 30:70 aqueous urea solutions. Isobaric crystallizations were carried out in glass capillaries, 0.30 mm in diameter. The capillary was mounted on an Oxford Diffraction SuperNova diffractometer operated with an X-rays CuKα microsource and equipped with an Oxford Cryosystem low-temperature attachment.

Figure 3. Pressure dependence of molecular volume (V/Z) in urea phases I (black circles), III (pink circles) and IV (orange circles). Empty black and pink circles show the molecular volume at 0.1 MPa and 0.50, 1.10, 2.20, 3.40, 4.20 GPa/296 K reported in ref 33.

The 50:50 solution crystallized at 263 K, and the 30:70 solution at about 250 K (see Figure S1 in Supporting Information). The in situ precipitated polycrystalline mass was examined by B


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The Journal of Physical Chemistry C X-ray powder diffraction (XRPD). In both samples only the reflections of urea I and ice Ih were identified. We also cycled temperature−decreased it to the point when most of the sample dissolved and lowered again slowly until all the sample froze. We used this procedure to grow single crystals of aqueous solutions of different concentrations, and in this experiment we checked if the sample history and varying kinetic conditions can promote hydration of urea. All these X-ray diffraction patterns revealed priscine urea and ice Ih only. High-pressure structural studies on urea was performed on the single crystals obtained in situ in the DAC from urea:water solutions, 1:1, 1:2, and 1:3 in volume. The crystal of phase III was grown from methanol:ethanol:water 16:3:1 mixture (Figure 2; see Figures S2−S4 in Supporting Information). The crystal of phase IV was obtained by gradually increasing pressure. Single crystal diffraction data were collected at 0.15, 0.32, 0.55, 1.00, 1.34, 1.48, 2.20, 2.50, 2.75, and 2.96 GPa/296 K.

Pressure in the DAC chamber was calibrated by the rubyfluorescence method,51 with a Photon Control Inc. spectrometer, affording an accuracy of 0.02 GPa. The spectrometer was optimized and calibrated to 694.54 nm and its resolution increased by expanding the spectral range of 22 nm to 2800 active pixels (a pixel resolution better than 0.008 nm), and the effective spectral resolution of 0.05 nm was derived from the repetitive measurements of low-pressure Ne lamp and ruby samples. Single-crystal high-pressure data were recorded on a KUMA KM4-CCD diffractometer according to the measurement procedure described previously.52 The CrysAlis software53 was used for the data collections and the preliminary reduction of the data. The intensities were corrected for the effects of DAC absorption, the sample shadowing by the gasket and the sample absorption,54,55 and the reflections overlapped with diamond reflections were eliminated. The urea phases were unequivocally determined from the unit-cell dimensions and space-groups symmetry and their structures were refined by full-matrix leastsquares.56 Anisotropic temperature factors were generally applied for non-hydrogen atoms. The H atoms were located from molecular geometry, their Uiso’s constrained to 1.2 times Ueq of their carrier atoms. Structural drawings were prepared using program Mercury CSD 3.3.57 All the dimensions involving H atoms at 0.1 MPa have been calculated for the H atoms located from molecular geometry using the same criteria, to avoid errors in the comparisons. The selected crystal data are listed in Tables 1 and S1 in Supporting Information. The crystal data have been deposited in the Cambridge Crystallographic Database Centre as a Supplementary publication CCDC (1517197−1517205) and in the Crystallography Open Database (COD). These data can be obtained free of charge via http://www.ccdc.cam.ac.uk/conts/retrieving.html and http://www.crystallography.net/cod/. We have also attempted to determine the structure of phase II, reported basing on the volumetric measurements by Bridgman.23,24 The DAC equipped with an internal heater mounted around the anvils and temperature controller stabilizing temperature within 0.1 K were used for high-pressure hightemperature experiments at 0.8 GPa/413 K and 0.9 GPa/393 K. Both techniques of (i) the in situ crystallization of the single crystal of phase II in its stability region and (ii) of heating the crystal grown in phase III to the region of phase II were applied, however in neither of these experiments a new phase of urea (different from phase III) could be found.

Figure 4. Unit-cell compression of urea phases I, III, and IV determined by single-crystal diffraction (full symbols). The data at 0.47, 0.80, 1.48, and 3.10 GPa/296 K were reported in ref 27. Empty circles, triangles, and squares show the molecular volume at 0.1 MPa and 0.50, 1.10, 2.20, 3.40, 4.20 GPa/296 K reported in ref 33. The pressure regions of phases I, III, and IV are highlighted gray, pink and yellow, respectively. The inset illustrates the unit-cell distortions between phases I (black), III (red), and IV (green).

Figure 5. Giant strain between urea phases I, III and IV illustrated by the same fragment of 5 × 5 molecules extending along the (100) plane, drawn as the space-filling model in a common scale (cf. Table 1 and note the unit-cell doubling along c). C


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The Journal of Physical Chemistry C

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RESULTS AND DISCUSSION The compression and phase transitions in urea are most intriguing in several respects, one of which is its anomalous strain at 0.48 GPa, to our knowledge the strongest ever recorded

for crystals. In order to monitor the lattice and structural changes close to the phase transitions in urea, we have presently obtained new data complementing the previous results, as illustrated in Figures 3 and 4. The crystal volume drops considerably at both the transitions at 0.48 and 2.80 GPa. The measured crystal data confirms an unprecedented anomalous strain associated with the transition at 0.48 GPa, involving extremely strong discontinuous positive linear compression along the [100] and exceptionally large negative linear compression along the [010] direction, as illustrated in Figure 4. The strong volume drop by over 7% at 0.48 GPa indicates that the driving force of the transitions is the volume reduction (Figure 3). The elimination of voids proceeds in two stages. At the first stage at 0.48 GPa, the voids partly collapse, every fourth of NH···O bonds breaks, the crystal symmetry lowers from space group P42̅ 1m to P212121 and the unit-cell parameter c doubles, due to the tilts of molecules in phase III (Figure 5). The potential energy (Ep) of the compressed structure computed by the PIXEL package,58 shown in Figure 6, abruptly rises at the phase transitions, which corresponds to the giant

Figure 6. Urea crystal potential energy Ep (red) calculated by program PIXEL58 and the −pδV work contribution (black) to the crystal energy change.

Figure 7. Hydrogen-bond lengths H···O (a) and N···H (c); as well as the shortest intermolecular distances N···O (b) and N···N (d) in the structures of urea phases I, III and IV. The vertical dotted lines mark the transitions and the horizontal dash-dotted line indicates the sums of van der Waals radii of H, N, and O atoms. The lines joining the points have been drawn for guiding the eye; double lines mark two symmetry-dependent H-bonds. Symmetry codes are listed in Table S2 in the Supporting Information. D


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The Journal of Physical Chemistry C anomalous strain of the crystal and very strong molecular rearrangements. The PIXEL calculations yielded the E p magnitudes slightly decreasing or constant with rising pressure within phases I, III, and IV. This would indicate that some structural changes compensate the work energy performed by the external pressure. In phase I, each molecule is the H-donor of four NH···O bonds and the H-acceptor of four such NH···O bonds. Thus, in the crystal there are four bonds NH···O per molecule and in the further discussion each molecule will be associated with its four H-donor bonds. At 0.48 GPa one of NH···O bonds is broken. We have found that the cleaved N2H2A···Oiii bond is substituted with bond N2H2A···N2ii (symmetry codes indicated by superscripts are listed in Table S2 in Supporting Information). Although this N2H2A···N2ii contact is weak according to the interatomic distances,59 only slightly shorter than the sum of van der Waals radii60 of N and H (2.58 Å at 0.48 GPa and 2.48 Å at 2.80 GPa, compared to de van der Waals radii sum of 2.75 Å), but it marks the beginning of a gradual shortening of N···N distances in the compressed crystal (Figure 7). It is characteristic that the N···N shortening mainly proceeds in steps at the phase transitions. Between 0.1 MPa and 3.0 GPa, the shortest N···N distances are reduced by about 0.5 Å, the next shortest by almost 0.8 Å, and the third shortest by about 0.95 Å, which contrasts with hardly any change of O···O distances of hydrogen bonds between phases I and IV. It can be noted that in the pressure range through phases I and III there are four H-bonds per one molecule: in phase I, four NH···O bonds, and in phase III, three bonds NH···O and one bond NH···N (N2···H2AiiN2ii). In phase IV, there are four NH···O and two very weak NH···N bonds (according to two intermolecular H···N distances slightly shorter than the sum of van der Waals radii, as illustrated in Figure 7). Noteworthy, these two shortest H···N contacts do not coincide with the shortest N···N contacts in phase IV. The first precise structural determinations of urea8,9 showed that the C−O distance is longer than expected for a double bond and C−N distance is shorter than a single bond of this type.5−9 Accordingly, it is generally assumed that the structure of urea molecule is that of a resonance hybrid present in the crystal at normal conditions.5−19 The contributing zwitterionic and molecular mesomers 1A, 1B, and 1C are shown in Figure 1. It appears from the molecular dimensions plotted in Figure 8 that the electronic structure of the molecule systematically changes with the increasing pressure. Initially, both independent bonds of C2v-symmetric molecule in phase I become somewhat shorter, up to the transition at 0.48 GPa. Then in phase III the bonds become longer and, as the molecular symmetry (of point group C2v in phase I) is reduced to point group C1, all the atoms are independent and bond C−N2 is systematically longer than C−N1. This length difference corresponds to the prevailing mesomer 1B in the molecular resonance structure. The changes in length of bonds C−N are consistent with the changes in their bond order.7,61 The changes in molecular dimensions can be connected with the changes in intermolecular interactions. The shortening of bonds C−N (by ca. 0.03 Å) and CO (by ca. 0.04 Å) within phase I can be connected with the increased squeezing force of the crystal environment on the molecule, without any significant change of the directions of hydrogen bonds. These shortenings are considerably stronger (about four times) than would be expected from the energy associated with the covalent bond C−C,62 which can suggest a contribution of mesomeric

Figure 8. Bond distances and angles in urea crystal phases I, III, and IV as a function of pressure.

transformations starting already in phase I. Moreover, the strong rearrangement at 0.48 GPa can release some of the strains accumulated in phase I along the bonds, which in phase III are replaced by more close contacts on both sides of the molecule. When combined with one NH···O bond cleaved and another one becoming longer, as well as one weak NH···N bond being formed in phase III, these changes in the crystal field considerably affects the molecular structure of urea, as observed by the lengthening of bonds C−N and CO (Figure 8). Previously an analogous pressure effect on the length of CO bonds in carbonyl groups involved in hydrogen bonds OH···O was reported.63 The different lengthening of bonds C−N1 and C−N2 can be correlated with their crystal environment significantly differentiated in phase III. The cleaved hydrogen bond involves atom N2 and these are two N2H2 groups of neighboring molecules that become weakly NH···N bonded, while no such changes occur to atom N1.

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CONCLUSIONS The present study of the structure of urea phases has shown that the high-pressure properties of this most important and abundant in Nature organic compound are likely to involve its mesomeric changes. We have shown that the anomalous strain in urea crystals at the phase transition at 0.48 GPa between phases I and III proceeds abruptly and to our knowledge is the strongest ever observed such an elongation in crystals, by more than 48% along [010]. The next strongest strain so far was observed in guanidinium nitrate at the transition at 298 K, where the crystals become longer by about 43%.64−66 Recently such giant strains were associated with distortions of metal−organic frameworks;67−70 however, the present study shows that molecular crystals of hydrogen-bonded small molecules can display similar or ever stronger effects. It is very plausible that the properties of E


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(8) Wyckoff, R. W. G.; Corey, R. B. Spectrometric Measurements on Hexamethylene Tetramine and Urea. Z. Kristallogr. - Cryst. Mater. 1934, 89, 462−468. (9) Vaughan, P. A.; Donohue, J. The Structure of Urea. Interatomic Distances and Resonance in Urea and Related Compounds. Acta Crystallogr. 1952, 5, 530−535. (10) Piasek, Z.; Urbański, T. The Infra-Red Absorption Spectrum and Structure of Urea. Bull. Acad. Polym. Sci. 1962, 10, 113−120. (11) Wheland, G. W. Resonance in Organic Chemistry; Wiley: New York, 1955; p 100. (12) Turner, E. E.; Harris, M. M. Organic Chemistry; Longmans, Green and Co: London, 1956; pp 128−129. (13) Morrison, R. T.; Boyd, R. N. Organic Chemistry; Allyn and Bacon Int.: Boston, MA, 1994; pp 257−261. (14) Berg, J. M.; Tymoczko, G. L.; Stryer, L. Biochemistry, 5th ed.; W. H. Freeman and Company: New York, 2002; pp 64−66. (15) Hart, H.; Craine, L. E.; Hart, D. J. Organic Chemistry a Short Course, 13th ed.; Houghton Mifflin Company: Boston, NY, 2016; p 315. (16) Wade, L. G., Jr. Organic Chemistry; Pearson: Upper Saddle River, NJ, 1999; p 1. (17) Peter, K.; Vollhardt, C.; Schore, N. E. Organic Chemistry: Structure and Function, 6th ed.; W. H. Freeman and Company: New York, 2009; pp 2−5. (18) Voet, D.; Voet, J. G. Biochemistry, 2nd ed.; Wiley and Sons Inc.: New York, 1995; pp 95−96. (19) McMurry, J. Organic Chemistry, 8th ed.; Cengage Learning: Boston, MA, 2011; pp 1−3. (20) Allen, F. H. The Cambridge Structural Database: a Quarter of a Million Crystal Structures and Rising. Acta Crystallogr., Sect. B: Struct. Sci. 2002, 58, 380−388. (21) Sun, H.; Kung, P. W. C. Urea: an Ab Initio and Force Field Study of the Gas and Solid Phases. J. Comput. Chem. 2005, 26, 169− 174. (22) King, S. T. Low Temperature Matrix Isolation Study of Hydrogen-Bonded, High-Boiling Organic CompoundsIII. Infrared Spectra of Monomeric Acetamide, Urea and Urea-d4. Spectrochim. Acta, Part A 1972, 28, 165−175. (23) Bridgman, P. W. Polymorphism at High Pressures. Proc. Am. Acad. Arts Sci. 1916, 52, 91−187. (24) Bridgman, P. W. The Velocity of Polymorphic Changes Between Solids. Proc. Am. Acad. Arts Sci. 1916, 52, 57−88. (25) Bridgman, P. W. Polymorphic Transitions up to 50,000 kg/cm2 of Several Organic Substances. Proc. Am. Acad. Arts Sci. 1938, 72, 227− 268. (26) Weber, H. P.; Marshall, W. G.; Dmitriev, V. High-Pressure Polymorphism in Deuterated Urea. Acta Crystallogr., Sect. A: Found. Crystallogr. 2002, 58, c174. (27) Olejniczak, A.; Ostrowska, K.; Katrusiak, A. H-Bond Breaking in High-Pressure Urea. J. Phys. Chem. C 2009, 113, 15761−15767. (28) Worsham, J. E.; Levy, H. A.; Peterson, S. W. The Positions of Hydrogen Atoms in Urea by Neutron Diffraction. Acta Crystallogr. 1957, 10, 319−323. (29) Pryor, A. W.; Sanger, P. L. Collection and Interpretation of Neutron Diffraction Measurements on Urea. Acta Crystallogr., Sect. A: Cryst. Phys., Diffr., Theor. Gen. Crystallogr. 1970, 26, 543−558. (30) Guth, H.; Heger, G.; Klein, S.; Treutmann, W.; Scheringer, C. Strukturverfeinerung von Harnstoff mit Neutronenbeugungsdaten bei 60, 123 und 293 K und X−N- und X−X(1s2)-Synthesen bei etwa 100 K. Z. Kristallogr. - Cryst. Mater. 1980, 153, 237−254. (31) Swaminathan, S.; Craven, B. M.; McMullan, R. K. The Crystal Structure and Molecular Thermal Motion of Urea at 12, 60 and 123 K from Neutron Diffraction. Acta Crystallogr., Sect. B: Struct. Sci. 1984, 40, 300−306. (32) Caron, A.; Donohue, J. Redetermination of Thermal Motion and Interatomic Distances in Urea. Acta Crystallogr., Sect. B: Struct. Crystallogr. Cryst. Chem. 1969, 25, 404.

urea are not only connected with the framework of hydrogen bonds in this structure, but that the hydrogen bonds transformations are coupled to the changes in the mesomeric structure of molecules. Such coupled transformations can be relevant to the structural phase transitions evidenced in analogous crystals: biurea,71 thiourea dioxide72 and in ionic crystals of urea nitrate73 and quanidium nitrate.64−66 More precise diffraction measurements are still needed for describing the mechanism of these transformations, particularly for phase IV, where the effect of pressure should be more apparent. Moreover, our exploration of the phase diagram of urea within the boundaries initially drawn by Bridgman23−25 for the elusive phase II, has not confirmed its existence. Therefore, further exploration of this T−p diagram region, by several different experimental techniques, is needed.

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ASSOCIATED CONTENT

S Supporting Information *

The Supporting Information is available free of charge on the ACS Publications website at DOI: 10.1021/acs.jpcc.6b11454. X-ray powder diffraction (XRPD), isochoric growth of the urea crystal in phases I and III; C−O···N angle of the hydrogen-bonds, angle C−O···H, angle N−H···O and N−H···N, and shortest intermolecular distances H···H (Figures S1−S8) and detailed crystallographic information and dimensions of hydrogen-bonds (Tables S1 and S2) (PDF)

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AUTHOR INFORMATION

Corresponding Author

*(A.K.) E-mail: [email protected]. ORCID

Andrzej Katrusiak: 0000-0002-1439-7278 Notes

The authors declare no competing financial interest.

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ACKNOWLEDGMENTS The computations were performed at the Poznan Supercomputing and Networking Centre. This study was performed within the scheme of statutory research financed by the Ministry of Science and Higher Education in the Faculty of Chemistry, Adam Mickiewicz University in Poznań, Poland.

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REFERENCES

(1) Wöhler, F. Ü ber Künstliche Bildung des Harnstoffe. Ann. Phys. 1828, 88, 253−256. (2) Becker, K.; Jancke, W. Röntenspektroskopische Untersuchungen an Organischen Verbindungen. I. Z. Phys. Chem. 1921, 99, 242−266. (3) Becker, K.; Jancke, W. Röntenspektroskopische Untersuchungen an Organischen Verbindungen. II. Z. Phys. Chem. 1921, 99, 267−274. (4) Mark, H.; Weissenberg, K. Röntgenographische Bestimmung der Struktur des Harnstoffs und des Zinntetrajodids. Eur. Phys. J. A 1923, 16, 1−22. (5) Pauling, L. Interatomic Distances in Covalent Molecules and Resonance Between Two or More Lewis Electronic Structures. Proc. Natl. Acad. Sci. U. S. A. 1932, 18, 293−297. (6) Pauling, L.; Sherman, J. The Nature of the Chemical Bond. VI. The Calculation from Thermochemical Data of the Energy of Resonance of Molecules Among Several Electronic Structures. J. Chem. Phys. 1933, 1, 606−617. (7) Pauling, L. The Nature of the Chemical Bond, 2nd ed.; Cornell University Press: Ithaca, NY, 1940. F


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(52) Budzianowski, A.; Katrusiak, A. In High-Pressure Crystallography; Katrusiak, A., McMillan, P. F., Eds., Kluwer: Dordrecht, 2004; pp 101−112. (53) Data collection and data reduction GUI. CrysAlisPro, version 1.171.33.61; Oxford Diffraction Ltd.: 2010. (54) Katrusiak, A. REDSHABS. Program for the Correcting Reflections Intensities for DAC Absorption, Gasket Shadowing and Sample Crystal Absorption; Adam Mickiewicz University: Poznań, Poland, 2003. (55) Katrusiak, A. Shadowing and Absorption Corrections of SingleCrystal High-Pressure Data. Z. Kristallogr. - Cryst. Mater. 2004, 219, 461−467. (56) Sheldrick, G. M. A Short History of SHELXL. Acta Crystallogr., Sect. A: Found. Crystallogr. 2008, 64, 112−122. (57) Macrae, C. F.; Edgington, P. R.; McCabe, P.; Pidcock, E.; Shields, G. P.; Taylor, R.; Towler, M.; van de Streek, J. Mercury: Visualization and Analysis of Crystal Structures. J. Appl. Crystallogr. 2006, 39, 453−457. (58) Gavezzotti, A. Calculation of Lattice Energies of Organic Crystals: the PIXEL Integration Method in Comparison with More Traditional Methods. Z. Kristallogr. - Cryst. Mater. 2005, 220, 499− 510. (59) Jeffrey, G. A.; Saenger, W. Hydrogen Bonding in Biological Structures; Springer -Verlag: Berlin and Heidelberg, Germany, 1991; pp 15−48. (60) Bondi, A. van der Waals Volumes and Radii. J. Phys. Chem. 1964, 68, 441−451. (61) Allmann, R. In Homoatomic Rings, Chains and Macromolecules of the Main Group Elements; Rheingold, A., Ed.; Elsevier: Amsterdam, 1977; pp 25−58. (62) Kitajgorodski, A. I. Kryształy Molekularne; PWN: Warsaw, 1976; pp 168−170. (63) Katrusiak, A. High-Pressure X-ray Diffraction Studies on Organic Crystals. Cryst. Res. Technol. 1991, 26, 523−531. (64) Katrusiak, A.; Szafrański, M. Structural Phase Transitions in Guanidinium Nitrate. J. Mol. Struct. 1996, 378, 205−223. (65) Szafrański, M.; Katrusiak, A. Temperature-Induced H-Site Centering in NH···O Hydrogen-Bonds of Quanidinium Nitrate by Neutron Diffraction. Chem. Phys. Lett. 2004, 391, 267−272. (66) Katrusiak, A.; Szafrański, M.; Podsiadło, M. Pressure-Induced Collapse of Quanidinium Nitrate N-H···O Bonded Honeycomb Layers into a 3-D Pattern with Varied H-Acceptor Capacity. Chem. Commun. 2011, 47, 2107−2109. (67) Cai, W.; Katrusiak, A. Giant Negative Linear Compression Positively Coupled to Massive Thermal Expansion in a Metal−Organic Framework. Nat. Commun. 2014, 5, 4337. (68) Cai, W.; Gładysiak, A.; Anioła, M.; Smith, V. J.; Barbour, L. J.; Katrusiak, A. Giant Negative Area Compressibility Tunable in a Soft Porous Framework Material. J. Am. Chem. Soc. 2015, 137, 9296−9301. (69) Goodwin, A. L.; Calleja, M.; Conterio, M. J.; Dove, M. T.; Evans, J. S. O.; Keen, D. A.; Peters, L.; Tucker, M. G. Colossal Positive and Negative Thermal Expansion in the Framework Material Ag3[Co(CN)6]. Science 2008, 319, 794−797. (70) Goodwin, A. L.; Keen, D. A.; Tucker, M. G. Large Negative Linear Compressibility of Ag3[Co(CN)6]. Proc. Natl. Acad. Sci. U. S. A. 2008, 105, 18708−18713. (71) Yan, T.; Wang, K.; Tan, X.; Yang, K.; Liu, B.; Zou, B. PressureInduced Phase Transition in N−H···O Hydrogen-Bonded Molecular Crystal Biurea: Combined Raman Scattering and X-Ray Diffraction Study. J. Phys. Chem. C 2014, 118, 15162−15168. (72) Wang, Q.; Yan, T.; Wang, K.; Zhu, H.; Cui, Q.; Zou, B. Pressure-Induced Reversible Phase Transition in Thiourea Dioxide Crystal. J. Chem. Phys. 2015, 142, 244701−7. (73) Li, S.; Li, Q.; Wang, K.; Zhou, M.; Huang, X.; Liu, J.; Yang, K.; Liu, B.; Cui, T.; Zou, G.; Zou, B. Pressure-Induced Irreversible Phase Transition in the Energetic Material Urea Nitrate: Combined Raman Scattering and X-Ray Diffraction Study. J. Phys. Chem. C 2013, 117, 152−159.

(33) Lamelas, F. J.; Dreger, Z. A.; Gupta, Y. M. Raman and X-Ray Scattering Studies of High-Pressure Phases of Urea. J. Phys. Chem. B 2005, 109, 8206−8215. (34) Girard, P.; Aliev, A. E.; Guillaume, F.; Harris, K. D. M.; Hollingsworth, M. D.; Dianoux, A.-J.; Jonsen, P. Reorientational Motions of Dioctanoyl Peroxide Guest Molecules within the Urea Tunnel Structure: Assessment of Two-Site Jump Models. Phys. B 1997, 234−236, 112−114. (35) Girard, P.; Aliev, A. E.; Guillaume, F.; Harris, K. D. M.; Hollingsworth, M. D.; Dianoux, A.-J.; Jonsen, P. Dynamic Properties of Dioctanoyl Peroxide Guest Molecules within the Urea Tunnel Structure: Incoherent Quasielastic Neutron Scattering and Solid State 2H NMR Investigations. J. Chem. Phys. 1998, 109, 4078−4089. (36) Hollingsworth, M. D.; Werner-Zwanziger, U.; Brown, M. E.; Chaney, J. D.; Huffman, J. C.; Harris, K. M. D.; Smart, S. P. SpringLoading at the Molecular Level: Relaxation of Guest-Induced Strain in Channel Inclusion Compounds. J. Am. Chem. Soc. 1999, 121, 9732− 9733. (37) Hollingsworth, M. D.; Peterson, M. L.; Pate, K. L.; Dinkelmeyer, B.; Brown, M. E. Unanticipated Guest Motion During a Phase Transition in a Ferroelastic Inclusion Compound. J. Am. Chem. Soc. 2002, 124, 2094−2095. (38) Hollingsworth, M. D.; Brown, M. E.; Dudley, M.; Chung, H.; Peterson, M. L.; Hillier, A. C. Template Effects, Asymmetry and Twinning in Helical Inclusion Compounds. Angew. Chem., Int. Ed. 2002, 41, 965−969. (39) Hollingsworth, M. D.; Peterson, M. L.; Rush, J. R.; Brown, M. E.; Abel, M. J.; Black, A. A.; Dudley, M.; Raghothamachar, B.; WernerZwanziger, U.; Still, E. J.; Vanecko, J. A. Memory and Perfection in Ferroelastic Inclusion Compounds. Cryst. Growth Des. 2005, 5, 2100− 2116. (40) Toudic, B.; Garcia, P.; Odin, C.; Rabiller, P.; Ecolivet, C.; Collet, E.; Bourges, P.; McIntyre, G. J.; Hollingsworth, M. D.; Breczewski, T. Hidden Degrees of Freedom in Aperiodic Materials. Science 2008, 319, 69−71. (41) Patyk, E.; Skumiel, J.; Podsiadło, M.; Katrusiak, A. HighPressure (+)-Sucrose Polymorph. Angew. Chem., Int. Ed. 2012, 51, 2146−2150. (42) Patyk, E.; Katrusiak, A. Transformable H-Bonds and Conformation in Compressed Glucose. Chem. Sci. 2015, 6, 1991− 1995. (43) Patyk, E.; Jenczak, A.; Katrusiak, A. Giant Strain Geared to Transformable H-Bonded Network in Compressed β-D-Mannose. Phys. Chem. Chem. Phys. 2016, 18, 11474−11479. (44) Tomkowiak, H.; Olejniczak, A.; Katrusiak, A. PressureDependent Formation and Decomposition of Thiourea Hydrates. Cryst. Growth Des. 2013, 13, 121−125. (45) Olejniczak, A.; Katrusiak, A. Pressure Induced Transformations of 1,4-Diazabicyclo[2.2.2]octane (Dabco) Hydroiodide: Diprotonation of Dabco, its N-Methylation and Co-Crystallization with Methanol. CrystEngComm 2010, 12, 2528−2532. (46) Andrzejewski, M.; Olejniczak, A.; Katrusiak, A. Remote Halogen Switch of Amine Hydrophilicity. CrystEngComm 2012, 14, 6374− 6376. (47) Fabbiani, F. P. A.; Allan, D. R.; David, W. I.; Moggach, S. A.; Parsons, S.; Pulham, C. R. High-Pressure Recrystallization - a Route to New Polymorphs and Solvates. CrystEngComm 2004, 6, 504−511. (48) Bruno, I. J.; Cole, J. C.; Edgington, P. R.; Kessler, M.; Macrae, C. F.; McCabe, P.; Pearson, J.; Taylor, R. New Software for Searching the Cambridge Structural Database and Visualizing Crystal Structures. Acta Crystallogr., Sect. B: Struct. Sci. 2002, 58, 389−397. (49) Merrill, L.; Bassett, W. A. Miniature Diamond Anvil Pressure Cell for Single Crystal X-Ray Diffraction Studies. Rev. Sci. Instrum. 1974, 45, 290−294. (50) Katrusiak, A. High-Pressure Crystallography. Acta Crystallogr., Sect. A: Found. Crystallogr. 2008, 64, 135−148. (51) Mao, H. K.; Xu, J.; Bell, P. M. Calibration of the Ruby Pressure Gauge to 800 kbar under Quasi-Hydrostatic Conditions. J. Geophys. Res. 1986, 91, 4673−4676. G


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