cis-(Nitrato-κ2 O,O′)(2,5,5,7,9,12,12,14-octa­methyl-1,4,8,11-tetra­aza­cyclo­tetra­decane-κ4 N,N′,N′′,N′′′)cadmium nitrate hemihydrate

Tapashi G Roy; Saroj K S Hazari; Babul Chandra Nath; Seik Weng Ng; Edward R T Tiekink

doi:10.1107/S160053681201238X

. 2012 Mar 28;68(Pt 4):m494–m495. doi: 10.1107/S160053681201238X

cis-(Nitrato-κ² O,O′)(2,5,5,7,9,12,12,14-octamethyl-1,4,8,11-tetraazacyclotetradecane-κ⁴ N,N′,N′′,N′′′)cadmium nitrate hemihydrate

Tapashi G Roy ^a,^‡, Saroj K S Hazari ^a, Babul Chandra Nath ^a, Seik Weng Ng ^b,^c, Edward R T Tiekink ^b,^*

PMCID: PMC3343882 PMID: 22589850

Abstract

The Cd^II atom in the title complex, [Cd(NO₃)(C₁₈H₄₀N₄)]NO₃·0.5H₂O, is coordinated within a cis-N₄O₂ donor set provided by the tetradentate macrocyclic ligand and two O atoms of a nitrate anion; the coordination geometry is distorted octahedral. The lattice water molecule is located on a twofold rotation axis. N—H⋯O hydrogen bonds and weak C—H⋯O interactions link the complex cations into a supramolecular layer in the bc plane. Layers are connected by O—H⋯O hydrogen bonds between the lattice water molecule and the non-coordinating nitrate anion, as well as by weak C—H⋯O contacts.

Related literature

For background to macrocyclic complexes, see: Hazari et al. (2008 ▶). For the crystal structure of the anhydrous form of the title complex, see: Hazari et al. (2010 ▶). For the synthesis of the macrocyclic ligand, see: Bembi et al. (1989 ▶).

Experimental

Crystal data

[Cd(NO₃)(C₁₈H₄₀N₄)]NO₃·0.5H₂O
M _r = 557.98
Monoclinic,
a = 18.4312 (4) Å
b = 11.3595 (2) Å
c = 25.1662 (6) Å
β = 111.782 (3)°
V = 4892.8 (2) Å³
Z = 8
Cu Kα radiation
μ = 7.55 mm⁻¹
T = 100 K
0.15 × 0.15 × 0.15 mm

Data collection

Agilent SuperNova Dual diffractometer with an Atlas detector
Absorption correction: multi-scan (CrysAlis PRO; Agilent, 2011 ▶) T _min = 0.738, T _max = 1.000
8065 measured reflections
4713 independent reflections
4467 reflections with I > 2σ(I)
R _int = 0.019

Refinement

R[F ² > 2σ(F ²)] = 0.029
wR(F ²) = 0.078
S = 1.06
4713 reflections
289 parameters
1 restraint
H atoms treated by a mixture of independent and constrained refinement
Δρ_max = 0.81 e Å⁻³
Δρ_min = −0.63 e Å⁻³

Data collection: CrysAlis PRO (Agilent, 2011 ▶); cell refinement: CrysAlis PRO; data reduction: CrysAlis PRO; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: ORTEP-3 (Farrugia, 1997 ▶) and DIAMOND (Brandenburg, 2006 ▶); software used to prepare material for publication: publCIF (Westrip, 2010 ▶).

Supplementary Material

Crystal structure: contains datablock(s) global, I. DOI: 10.1107/S160053681201238X/xu5483sup1.cif

e-68-0m494-sup1.cif^{(27.7KB, cif)}

Structure factors: contains datablock(s) I. DOI: 10.1107/S160053681201238X/xu5483Isup2.hkl

e-68-0m494-Isup2.hkl^{(231KB, hkl)}

Additional supplementary materials: crystallographic information; 3D view; checkCIF report

Table 1. Selected bond lengths (Å).

Cd—O1	2.4562 (19)
Cd—O2	2.404 (2)
Cd—N1	2.306 (2)
Cd—N2	2.307 (2)
Cd—N3	2.303 (2)
Cd—N4	2.312 (2)

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Table 2. Hydrogen-bond geometry (Å, °).

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
O1w—H1w⋯O5	0.85 (1)	2.04 (2)	2.836 (3)	156 (5)
N1—H1n⋯O1ⁱ	0.88	2.42	3.242 (3)	155
N2—H2n⋯O4	0.88	2.30	3.133 (4)	157
N4—H4n⋯O5	0.88	2.11	2.991 (3)	175
C5—H5B⋯O6ⁱⁱ	0.98	2.58	3.539 (5)	168
C11—H11⋯O4ⁱⁱⁱ	1.00	2.44	3.358 (3)	152
C9—H9B⋯O1w^iv	0.98	2.51	3.451 (4)	162

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Symmetry codes: (i) Inline graphic ; (ii) ; (iii) ; (iv) .

Acknowledgments

The authors are grateful to the Ministry of National Science, Information and Communication Technology (NSICT), Bangladesh, for a research fellowship to BCN. The authors also thank the Ministry of Higher Education (Malaysia) for funding structural studies through the High-Impact Research scheme (grant No. UM.C/HIR/MOHE/SC/12).

supplementary crystallographic information

Comment

In continuation of on-going studies of the synthesis, characterization and biological activities of substituted tetraazamacrocyclic ligands and their metal complexes (Hazari et al., 2008), attention was directed to cadmium complexes (Hazari et al., 2010). In that study, the title complex was investigated in its anhydrous form. Recently, it was isolated as a hemihydrate (I). Herein, we describe the crystal structure of (I).

In cation in (I), Fig. 1, the Cd^II atom exists within a cis-N₄O₂ donor set defined by the four nitrogen atoms of the macrocyclic ligand and two nitrate-O atoms, Table 1. The coordination geometry is based on an octahedron, but with significant distortions owing in part to the restricted bite angle of the nitrate ligand as manifested in the O1—Cd—O2 angle of 52.80 (7)°. A more regular geometry was found in the anhydrous form of the complex (Hazari et al., 2010). The N—H atoms are orientated oppositely going around the macrocyclic ring. The non-coordinating nitrate anion straddles one side of the cation forming two N—H···O hydrogen bonds and an eight-membered {···ONO···HNCdNH} synthon. The formation of N—H···O hydrogen bonds between a third amine-H and an oxygen atom of the coordinated nitrate ligand leads to four-ion aggregates. These are linked into a supramolecular layer in the bc plane via C—H···O interactions involving the non-coordinating nitrate anion, Fig. 2 and Table 2. The water molecules link layers in the a direction forming O—H···O hydrogen bonds with the O5 atom of the non-coordinating nitrate anion and C—H···O interactions, Fig. 3 and Table 2.

Experimental

The macrocyclic ligand, 3,10-C-meso-2,5,5,7,9,12,12,14-octamethyl-1,4,8,11-tetraazacyclotetradecane (0.312 g, 1.0 mmol), prepared in accord with the literature procedure (Bembi et al., 1989), was dissolved in methanol (20 ml) in a round bottomed flask. Cadmium(II) nitrate hexahydrate (0.344 g, 1.0 mmol) in methanol (20 ml) was added drop wise to the round bottom flask with continuous stirring The mixture was heated for about 30 min. on a steam bath to ensure the completion of the reaction and was then filtered. After 48 h, the white crystalline product that formed from the filtrate was filtered off, washed with methanol followed by diethylether and dried in a desiccator over silica gel. Yield 85%. M.pt: 515–518 K. Anal. Calc. for. C₁₈H₄₁CdN₆O_6.5 C, 38.75; H, 7.41; N, 15.06; Cd, 20.15%. Found: C, 38.85; H, 7.33; N, 15.75; Cd, 20.35%. FT—IR (KBr, cm^-1) 3200 ν(N—H), 2980 ν(C—H), 1371 ν(CH₃), 1178 ν(C—C), 520 ν(Cd—N), 1381, 1460, 1275, 730, 820 ν(NO₃).