Ζ. Kristallogr. NCSxvutsrponmlihfedcaSRGEDA 217 (2002) 535-536 535 ι by Oldenbourg Wissenschaft s verlag,zyxwvutsrponmlihgfedcbaXUTSRQPONMLJIHFEDCA München Crystal structure of iminodiacetic acid monomethyl ester monohydrate, C5H9NO4 · H2O M. Ramos Silva* 1 , A. Matos Beja 1 , J. A. Paixäo 1 , A. J. F. N. Sobral", L. M. L. Cabrai", S. H. Lopes" and Α . Μ . d'A. Rocha Gonsalves" 1 Universidade de Coimbra. Faculdade de Ciencias e Tecnologia, Departamento de Física, CEMDRX, P-3004-516 Coimbra, Portugal " Universidade de Coimbra. Faculdade de Ciencias e Tecnologia, Departamento de Química, P-3000 Coimbra, Portugal Received July 12, 2002. accepted and available on-line September 24, 2002; CCDC-No. 1267/900 Abstract C5H11NO5, monoclinic, P12i/cl (No. 14), a = 5.212 Â, trpmifbaVNK b= 16.881 Â , c = 10.116 Â,/?= 119.09°, V= 777.8 Â 3 , Ζ = 4,wtsrolkihfebaRNKF R#(F) = 0.058, wRrefiF 1 ) = 0.180, Τ = 293 Κ. Source of material A mixture of iminodiacetic acid (16.8 g, 0.13 mol), thionyl chlo- ride (30.9 g, 0.26 mol) and methanol (85 ml) was placed in a 250 ml round bottoned flask fitted with a reflux condenser and a silica guard tube. The mixture was stirred and heated under reflux for 4 hours. The solution was then washed with water/dichloro- methane and the organic layer dried with anhydrous Na2SC>4, evaporated under reduced pressure and left to crystallise from di- chloromethane/n-hexane. The (methoxycarbonylmethyl- amino)-acetic acid was obtained with 15% yield. Melting point: 411 Κ - 413 Κ. Ft-IR (cm -1 ; group): (1643; C=0 ketone form), (3503; Ν—H). Experimental details The structure was solved by direct methods. The hydrogen atoms of the main residue were placed at calculated positions and re- fined as riding using the SHELXL-97 defaults [1], The crystal structure contains one water molecule disordered over three posi- tions, sum of the their freely refined occupancies is 1.00(3). The isotropic temperature factors of the three water O atoms were constrained to be equal, the water Η atoms could not be located. Discussion Iminodiacetic acid and its derivatives are important compounds in coordination chemistry. The presence of two close carboxylic groups makes this molecule and its derivatives excellent ion coor- dination agents. This property has been fully exploited in the preparation of modified polymers and resins for ion capture, both for analytical [2-4] or industrial uses [5,6]. In medical related sci- ences, iminodiacetic acid derivatives are used as solid phase sup- ports for peptide synthesis [7] and as base for chemical libraries in combinatory chemistry [8]. Iminodiacetic acid is also of great im- portance in organic chemistry, namely on the synthesis of maleimides [9] and 3,4 di-substituted pyrroles [10] by Friedman method. Following the preparation of the manganese complex of -octaphenyl-porphyrin for our studies of metalloporphyrin-based oxidation of hydrocarbons [11], we synthesised several imino- diacetic derivatives as pyrrole precursors, amongst them, the title compound. The conformation of the zwitterion is close to that found in the second polymorph form of iminodiacetic acid, IMDA2 [12]. The C4 atom is gauche to C1 when the ion is viewed along Ν—C3 and with C3 trans to C2 when viewed along Ν—C1. The formal negative charge is spread over the carboxylate group 03-C4-04 (C—O distances are: d(C4—03) = 1.250(2) Â, d(C4—04) = 1.243(3) Â). The bond distances of the carboxylic acid group in- dicate one double bond (d(C2=02) = 1.196(3) Â) and one single bond (d(C2—Ol) = 1.326(3) Â). The substituted half of the iminodiacetic acid molecule is approximated planar with Cl, C2, 01,02, C5 lying in a plane (rms deviation from L.S. plane 0.02 À), the nitrogen atom is 0.186(3) Â away from that plane. The zwitteri- ons are bonded together by hydrogen bonds forming layers. The ni- trogen atom donates its two hydrogen atoms to the oxygen atoms of the carboxylate groups of neighbouring molecules (N-Hl —03': 2.670(3) Â, 176.2°, 1: x+l, -y-1/2, z+1/2; N-H2-04": 2.986(3) A, 139.0°, ii: x+l.y, z). Using graph-set analysis [13] one recognise at the unitary level, chains of degree 5 running along the [ 100] and [201] directions. In the second polymorph form of iminodiacetic acid, one of the N-H—O bonds also forms a chain of degree 5 while the other displays only discrete patterns [13]. Table 1. Data collection and handling. Crystal: colourless prism, size 0.08 χ 0.10 χ 0.42 mm Wavelength: Cu Ka radiation (1.54180 Â) ft- 11.06 cm" 1 Diffractometer, scan mode: Enraf-Nonius Mach 3, ω/2θ 20max: 144.88° Admeasured, JVfAWjunique: 3178, 1550 Criterion for lobs, Nfhktfe: Jobs > 2 af/obs), 1346 N(param) Kñaa ¡: 105 Programs: SHELXS-97 [14], SHELXL-97 [1], PLATON [15], ORTEPn [16] * Correspondence author (e-mail: manuela@pollux.fis.uc.pt) Unauthenticated Download Date | 7/27/18 7:28 PM