The structure of the title compound, [Cu2Cl2(C4H13N3)2(H2O)]Cl2, at 180 K is described in space group P21/n with a unit-cell volume twice that reported previously for the structure at 293 K [Willett (2001[Willett, R. D. (2001). Acta Cryst. E57, m605-m606.]). Acta Cryst. E57, m605-m606]. In the smaller unit cell, in space group P21/m, the complex has imposed mirror symmetry and unusually elongated displacement ellipsoids. At 180 K, refinement in the larger unit cell with no imposed symmetry resolves this issue. With room-temperature data collected from the same crystal, however, refinement using the larger unit cell gives no significant improvement, and the previously reported structure is considered to be most appropriate

Bond, A.

Creaven, S.

Gernon, T.

McGinley, John

English

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electronic reprintActa Crystallographica Section EStructure ReportsOnlineISSN 1600-5368Editors: W. Clegg and D. G. WatsonAquadi- -chloro-bis(diethylenetriamine)dicopper(II) dichloride: aredetermination at 180 KTammy L. Gernon, Bernadette S. Creaven, John McGinley and Andrew D. BondCopyright © International Union of CrystallographyAuthor(s) of this paper may load this reprint on their own web site provided that this cover page is retained. Republication of this article or itsstorage in electronic databases or the like is not permitted without prior permission in writing from the IUCr.Acta Cryst. (2006). E62, m1958–m1960 Gernon et al.   [Cu2Cl2(C4H13N3)2(H2O)]Cl2metal-organic papersm1958 Gernon et al.  [Cu2Cl2(C4H13N3)2(H2O)]Cl2 doi:10.1107/S1600536806028212 Acta Cryst. (2006). E62, m1958–m1960Acta Crystallographica Section EStructure ReportsOnlineISSN 1600-5368Aquadi-l-chloro-bis(diethylenetriamine)dicopper(II)dichloride: a redetermination at 180 KTammy L. Gernon,aBernadette S. Creaven,b JohnMcGinleya and Andrew D.Bondc*aDepartment of Chemistry, National Universityof Ireland Maynooth, Maynooth, CountyKildare, Ireland, bDepartment of AppliedScience, Institute of Technology, Tallaght,Dublin 24, Ireland, and cDepartment of Physicsand Chemistry, University of Southern Denmark,Campusvej 55, 5230 Odense M, DenmarkCorrespondence e-mail: adb@chem.sdu.dkKey indicatorsSingle-crystal X-ray studyT = 180 KMean (C–C) = 0.002 A˚R factor = 0.020wR factor = 0.054Data-to-parameter ratio = 20.4For details of how these key indicators wereautomatically derived from the article, seehttp://journals.iucr.org/e.Received 3 July 2006Accepted 20 July 2006# 2006 International Union of CrystallographyAll rights reservedThe structure of the title compound, [Cu2Cl2(C4H13N3)2-(H2O)]Cl2, at 180 K is described in space group P21/n with aunit-cell volume twice that reported previously for thestructure at 293 K [Willett (2001). Acta Cryst. E57, m605–m606]. In the smaller unit cell, in space group P21/m, thecomplex has imposed mirror symmetry and unusuallyelongated displacement ellipsoids. At 180 K, refinement inthe larger unit cell with no imposed symmetry resolves thisissue. With room-temperature data collected from the samecrystal, however, refinement using the larger unit cell gives nosignificant improvement, and the previously reported struc-ture is considered to be most appropriate.CommentThe crystal structure of the title compound, (I), at 293 K hasbeen reported previously (Willett, 2001). The structure wasdescribed in space group P21/m, with unit-cell parameters a =6.7155 (8), b = 14.6106 (11) and c = 10.3011 (8) A˚, and  =95.333 (10). In this description, the dinuclear cation exhibitscrystallographic mirror symmetry, with the mirror planepassing through all four atoms of the central Cu2Cl2 unit, thecentral N atom of each diethylenetriamine ligand and thewater molecule bound to one of the CuII ions. Crystals of thetitle compound were obtained inadvertently as a by-product ofan intended synthesis, and examined at 180 K. At the lowertemperature, the structure is best described in space groupP21/n with a unit-cell volume twice that of Willett’s descrip-tion. The P21/n and P21/m descriptions are clearly related:transformation of Willett’s unit cell by the matrix [1 0 1 / 01 0/ 1 0 1] yields the unit cell a = 11.762, b = 14.611 and c =12.809 A˚, and  = 113.89. In the larger unit cell, the complexexhibits no crystallographic symmetry (Fig. 1).In the structure reported by Willett, the diethylenetriamineligand bound to the five-coordinate CuII ion displays signifi-cantly elongated displacement ellipsoids, while the ligandbound to the six-coordinate CuII ion appears more usual.Willett noted that this may be ‘indicative of unresolveddisorder’. The observation can be accounted for by consid-electronic reprintering the P21/n structure. The coordination environment ofeach CuII ion exhibits a local mirror plane: for Cu1, this planepasses through atoms Cu1, N2, O1 and Cl1, while for Cu2, theplane passes through atoms Cu2, Cl2, Cl1 and N5. These twoplanes are not coincident, forming a dihedral angle of 6.4 (1).If the P21/n structure is transformed into the smaller unit cell(transformation matrix [12 012 / 0 1 0 / 12 0 12]) and described inspace group P21/m, the mirror plane through atoms Cu1, N2,O1 and Cl1 becomes crystallographic, but the local mirrorplane through atoms Cu2, Cl2, Cl1 and N5 does not coincidewith this plane. As a result, application of the crystallographicmirror symmetry produces two closely spaced atomic positionsfor each of the atoms of the diethylenetriamine ligand boundto Cu2. In the P21/m description, each such pair is averagedinto a single atomic position with an elongated displacementellipsoid. For the 180 K data, refined using the smaller unitcell, this elongation is dramatic and clearly unacceptable(Fig. 2).In order to assess whether Willett’s structure represents afair description at 293 K, data were re-collected from the samecrystal at room temperature. When described by the largerunit cell, reflections (hkl) with h+l odd become systematicallyweak, indicating pseudo-B-centring. If this centring weregenuine, the unit cell should be transformed to the smallerdescription in P21/m. Of 39 277 such reflections measured,3653 were observed at the 3(I) level, although the meanI/(I) for all these reflections is only 1.1. Refinement in thelarger unit cell produces a structure in which the local mirrorplanes through each CuII ion are much closer to coincidence[dihedral angle 1.5 (1)], and the bond lengths of the complexrelated by the pseudo-mirror plane do not differ significantly.In addition, the displacement ellipsoids of the diethylene-triamine ligand bound to Cu2 become elongated (Fig. 3).Although the elongation is less dramatic than that reported byWillett, the shapes of the displacement ellipsoids are closelycomparable for the same data set refined using eitherdescription of the structure. Under these circumstances, nosignificant improvement is achieved by refinement in thelarger unit cell, and Willett’s structure should therefore beconsidered more appropriate at 293 K.ExperimentalCrystals of (I) were obtained as a decomposition product from thereaction of a bis[(methylamide)ethyl]amino-substituted tert-butyl-calix[4]arene with copper(II) chloride in a 1:1 ratio in refluxingmethanol. The compound can be prepared directly by the procedurereported previously (Willett, 2001).Crystal data[Cu2Cl2(C4H13N3)2(H2O)]Cl2Mr = 493.24Monoclinic, P21=na = 11.6882 (5) A˚b = 14.5158 (6) A˚c = 12.7477 (6) A˚ = 114.124 (1)V = 1973.93 (15) A˚3Z = 4Dx = 1.660 Mg m3Mo K radiation = 2.70 mm1T = 180 (2) KBlock, blue0.30  0.20  0.15 mmmetal-organic papersActa Cryst. (2006). E62, m1958–m1960 Gernon et al.  [Cu2Cl2(C4H13N3)2(H2O)]Cl2 m1959Figure 1The asymmetric unit of (I) in the larger unit cell (space group P21/n) at180 K, showing the atom-numbering scheme. Displacement ellipsoids aredrawn at the 50% probability level and H atoms are shown as spheres ofarbitrary radii.Figure 2The cationic complex in (I) refined in the smaller unit cell (space groupP21/m) at 180 K, with displacement ellipsoids drawn at the 50%probability level. H atoms have been omitted. The grossly distorteddisplacement parameters are a result of site averaging imposed by falsemirror symmetry. [Symmetry code (i): x, 12  y, z].Figure 3The cationic complex in (I) refined in the larger unit cell (space groupP21/n) at 293 K, with displacement ellipsoids drawn at the 50%probability level. H atoms have been omitted.electronic reprintData collectionBruker Nonius X8 APEXII CCDarea-detector diffractometerThin–slice ! and ’ scansAbsorption correction: multi-scan(SADABS; Sheldrick, 2003)Tmin = 0.483, Tmax = 0.69146464 measured reflections4892 independent reflections4308 reflections with I > 2(I)Rint = 0.030max = 28.3RefinementRefinement on F 2R[F 2 > 2(F 2)] = 0.020wR(F 2) = 0.054S = 1.104892 reflections240 parametersH atoms treated by a mixture ofindependent and constrainedrefinementw = 1/[2(Fo2) + (0.028P)2+ 0.4572P]where P = (Fo2 + 2Fc2)/3(/)max = 0.002max = 0.38 e A˚3min = 0.82 e A˚3Table 1Selected bond lengths (A˚).Cu1—Cl1 2.2813 (3)Cu1—Cl2 3.0330 (4)Cu1—N1 2.0009 (11)Cu1—N2 2.0037 (11)Cu1—N3 2.0001 (11)Cu1—O1 2.5740 (12)Cu2—Cl1 2.6495 (4)Cu2—Cl2 2.2792 (4)Cu2—N4 1.9938 (11)Cu2—N5 2.0139 (11)Cu2—N6 2.0000 (11)Table 2Hydrogen-bond geometry (A˚, ).D—H  A D—H H  A D  A D—H  AO1—H1  Cl3 0.76 (2) 2.42 (2) 3.1451 (12) 163 (2)O1—H2  Cl4 0.75 (2) 2.39 (2) 3.1229 (11) 163 (2)N1—H11  Cl4 0.86 (1) 2.53 (1) 3.3252 (12) 155 (1)N1—H12  Cl4i 0.86 (1) 2.49 (1) 3.3045 (11) 159 (2)N2—H21  Cl1ii 0.84 (1) 2.54 (1) 3.2448 (12) 143 (2)N3—H31  Cl3 0.86 (1) 2.79 (1) 3.5294 (12) 145 (1)N3—H32  Cl3iii 0.85 (1) 2.45 (1) 3.2666 (11) 162 (2)N4—H42  Cl3iii 0.86 (1) 2.55 (1) 3.3721 (12) 160 (2)D—H  A D—H H  A D  A D—H  AN4—H41  Cl4iv 0.85 (1) 2.48 (1) 3.2901 (12) 160 (1)N5—H51  Cl2v 0.84 (1) 2.49 (1) 3.2882 (11) 160 (2)N6—H61  Cl3iv 0.85 (1) 2.48 (1) 3.2707 (12) 156 (1)N6—H62  Cl4i 0.86 (1) 2.55 (1) 3.3063 (11) 147 (1)Symmetry codes: (i) xþ 1;y;zþ 1; (ii) xþ 12;yþ 12; zþ 12; (iii)x þ 1;yþ 1;zþ 1; (iv) x 12;yþ 12; zþ 12; (v) x 12;y þ 12; z 12.H atoms bound to C atoms were positioned geometrically andallowed to ride during subsequent refinement, with C—H = 0.99 A˚and Uiso(H) = 1.2Ueq(C). H atoms bound to N and O atoms werelocated in difference Fourier maps and refined with isotropicdisplacement parameters. The two O—H distances were restrained toa common value and the H  H distance was restrained to 1.58 timesthat value. All N—H distances were restrained to a common valueand the H  H distance (where appropriate) was restrained to 1.63times that value. The refined parameters were 0.75 (2) and 0.85 (1) A˚for O—H and N—H, respectively.Data collection: APEX2 (Bruker Nonius, 2004); cell refinement:SAINT (Bruker, 2003); data reduction: SAINT; program(s) used tosolve structure: SHELXTL (Sheldrick, 2000); program(s) used torefine structure: SHELXTL; molecular graphics: SHELXTL; soft-ware used to prepare material for publication: SHELXTL.The authors are grateful to the Danish Natural ScienceResearch Council (SNF) and Carlsbergfondet for provision ofthe X-ray equipment.ReferencesBruker (2003). SAINT. Version 7.06a. Bruker AXS Inc., Madison, Wisconsin,USA.Bruker Nonius (2004). APEX2. Version 1.0-22. Bruker Nonius BV, Delft, TheNetherlands.Sheldrick, G. M. (2000). SHELXTL. Version 6.10. Bruker AXS Inc., Madison,Wisconsin, USA.Sheldrick, G. M. (2003). SADABS. Version 2.10. Bruker AXS Inc., Madison,Wisconsin, USA.Willett, R. D. (2001). Acta Cryst. E57, m605–m606.metal-organic papersm1960 Gernon et al.  [Cu2Cl2(C4H13N3)2(H2O)]Cl2 Acta Cryst. (2006). E62, m1958–m1960electronic reprint

Aquadi-u-chloro-bis(diethylenetriamine)dicopper(11) dichloride: A redetermination at 180 K

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Aquadi-u-chloro-bis(diethylenetriamine)dicopper(11) dichloride: A redetermination at 180 K

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