Hydro­gen bonds in the framework of bis{2-[bis(2-amino­ethyl)­amino]­ethanol}nickel(II) diperchlorate

The title molecule, [Ni(C₆H₁₇N₃O)₂](ClO₄)₂, possesses a crystallographic centre of symmetry at the Ni^II position. The coordination geometry around the Ni^II atom is distorted octahedral, consisting of six N atoms from two tripodal poly­amine ligands, while the ethanol O atoms of the ligands remain uncoordinated. The crystal packing shows two-dimensional layers and an infinite three-dimensional framework which is stabilized by a hydrogen-bonded network.

S1. Comment

Nonredox-active metals such as Ni^II and Zn^II are potentially of interest as hydrolytic cleaving agents of DNA, and their reactivity in model systems may lead to functional DNA cleaving molecules. Metal-polyamine complexes of Ni^II or Zn^II are frequently used as models for hydrolases. Among the polyamine ligands designed, tripodal polyamines are especially of interest owing to their implication in a wide variety of biochemical and supramolecular systems (Mao et al., 1993; Anderegg & Gramlich, 1994; Murthy & Karlin, 1993; Lu et al., 1998). Some reported Ni^II-tripodal polyamine complexes exhibit very high hydrolytic activity towards phosphate esters and are potential artificial DNA-cut agents (De Rosch & Trogler, 1990; Tafesse et al., 1993). In the course of our work on synthesis of metal-asymmetric tripodal heteropolyamine complexes, we obtained a new 1:2 Ni^II—L complex, the title complex, with a structure of firstly infinite two-dimensional layers, then infinite three-dimensional framework stabilized by the hydrogen-bond network. \sch

As depicted in Fig. 1, Ni^II is located at the symmetric center and exhibits a slightly distorted octahedral geometry with six nitrogen atoms from two of the tripodal polyamine ligands. Four primary amine N atoms form the equatorial plane in which the Ni^II atom lies almost in the middle with equal Ni^II—N distances [Ni^II—N2 = Ni^II—N2(-x, -y, -z) = 2.122 Å, Ni^II—N3 = Ni^II—N3(-x, -y, -z) = 2.129 Å], while the apical N atom (tertiary amine N atom) is a little bit further from the central Ni^II atom [Ni^II—N1= Ni^II—N1(-x, -y, -z) = 2.191 Å]. All the N—Ni^II—N bond angles range from 82.32° to 91.17°. The perchlorate anions ClO₂O₃O₄O₅ and Cl'O₂'O₃'O₄'O₅' are disorder, with occupancy factors of 0.50. Six kinds of hydrogen disordered bonds occur in the structure. The hydrogen bond between O1 of the ethoxyl-pod and N3 of ethenyl amine pod of the adjacent ligand [N3—H3a—O1(0.5 - x, -0.5 + y, 0.5 - z), N3—O1 = 3.114 Å and N3—H3a—O1 154.5°] is responsible for the formation of the two-dimensional sheet-like Ni^II—L₂ cation polymers which spread along the (1, 0, -1) plane to form an infinite network (see Fig. 2). Three kinds of additional hydrogen bonds exist inside the layer between the nitrogen atoms of the ethenyl amine pods and perchlorate anions: N2—H2a—O3(-x, -y, -z), N2—O3 = 3.156 Å and N2—H2a—O3 161.02°; N3—H3b—O4(-x, -y, -z), N3—O4 = 3.089 Å and N3—H3b—O4 155.01°; N3—H3b—O4'(-x, -y, -z), N3—O4' = 3.038 Å and N3—H3b—O4' 170.87°. The other two kinds of hydrogen bond [O1—H1— O2(1 + x, y, z), O1—O2 = 2.895 Å and O1—H1—O2 168°; O1—H1—O2'(1 + x, y, z), O1—O2' = 3.041 Å and O1—H1—O2' 162°] between oxygen of the ethoxyl-pod and perchlorate anions cross-link the layers into one three-dimensional framework, as is depicted in Fig 2.

S2. Experimental

The title compound was synthesized by mixing the ligand 2-[bis(2-aminoethyl)amino]ethanol (0.147 g, 1 mmol) and Ni^II(ClO₄)₂. 6H₂O (0.366 g, 1 mmol) in water. Purple crystals were obtained upon evaporation.

S3. Refinement

Data were corrected for Lorentz and polarization effects. The H atoms were geometrically fixed.

Computing details

Data collection: XSCANS (Siemens, 1994); cell refinement: XSCANS; data reduction: SHELXTL (Sheldrick, 1990); program(s) used to solve structure: SHELXS97 (Sheldrick, 1990); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: SHELXTL; software used to prepare material for publication: SHELXTL.

Figures

	Fig. 1. The molecular structure of (I) showing 30% probability displacement ellipsoids and atom-numbering scheme. H atoms have been omitted for clarity. [Symmetry code: (i) -x, -y, -z.]
	Fig. 2. A view of the two-dimensional network along the (1,0,-1) plane. Unrelated H atoms and perchlorate anions have been omitted for clarity.
	Fig. 3. Packing diagram viewed down the b axis, showing the three-dimensional framework.

Bis{2-[bis(2-aminoethyl)amino]ethanol}-nickel(II) perchlorate

Crystal data

[Ni(C6H17N3O)2](ClO4)2	F(000) = 580
Mr = 552.06	Dx = 1.648 Mg m^−3
Monoclinic, P21/n	Mo Kα radiation, λ = 0.71073 Å
a = 9.026 (1) Å	Cell parameters from 25 reflections
b = 12.623 (2) Å	θ = 3.0–16.2°
c = 10.683 (1) Å	µ = 1.17 mm^−1
β = 113.90 (1)°	T = 298 K
V = 1112.8 (2) Å^3	Prism, purple
Z = 2	0.50 × 0.44 × 0.32 mm

Data collection

Siemens P4 diffractometer	1700 reflections with I > 2σ(I)
Radiation source: normal-focus sealed tube	Rint = 0.016
Graphite monochromator	θmax = 25.5°, θmin = 2.5°
ω scans	h = 0→10
Absorption correction: empirical (using intensity measurements) (North et al., 1968)	k = 0→15
Tmin = 0.598, Tmax = 0.687	l = −12→11
2397 measured reflections	3 standard reflections every 97 reflections
2061 independent reflections	intensity decay: 2.3%

Refinement

Refinement on F^2	Secondary atom site location: difference Fourier map
Least-squares matrix: full	Hydrogen site location: inferred from neighbouring sites
R[F^2 > 2σ(F^2)] = 0.037	H atoms treated by a mixture of independent and constrained refinement
wR(F^2) = 0.105	w = 1/[σ^2(Fo^2) + (0.0669P)^2 + 0.1837P] where P = (Fo^2 + 2Fc^2)/3
S = 1.06	(Δ/σ)max = 0.001
2061 reflections	Δρmax = 0.59 e Å^−3
192 parameters	Δρmin = −0.39 e Å^−3
10 restraints	Extinction correction: SHELXL97 (Sheldrick, 1997), Fc^*=kFc[1+0.001xFc^2λ^3/sin(2θ)]^-1/4
Primary atom site location: structure-invariant direct methods	Extinction coefficient: 0.0079 (18)

Special details

Geometry. All e.s.d.'s (except the e.s.d. in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell e.s.d.'s are taken into account individually in the estimation of e.s.d.'s in distances, angles and torsion angles; correlations between e.s.d.'s in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell e.s.d.'s is used for estimating e.s.d.'s involving l.s. planes.

Refinement. Refinement of F² against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F², conventional R-factors R are based on F, with F set to zero for negative F². The threshold expression of F² > σ(F²) is used only for calculating R-factors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on F² are statistically about twice as large as those based on F, and R- factors based on ALL data will be even larger.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Ų)

	x	y	z	Uiso*/Ueq	Occ. (<1)
Ni	0.0000	0.0000	0.0000	0.03322 (19)
O1	0.3478 (3)	0.3406 (2)	0.0922 (3)	0.0696 (7)
N1	0.1795 (3)	0.11752 (18)	0.0019 (2)	0.0399 (5)
N2	0.0635 (3)	−0.07110 (19)	−0.1514 (3)	0.0475 (6)
H2A	0.0853	−0.1402	−0.1320	0.057*
H2B	−0.0203	−0.0661	−0.2338	0.057*
N3	0.2068 (3)	−0.06743 (19)	0.1594 (2)	0.0450 (6)
H3A	0.1894	−0.0718	0.2364	0.054*
H3B	0.2231	−0.1334	0.1355	0.054*
C1	0.2132 (5)	0.0962 (3)	−0.1195 (4)	0.0661 (10)
H1A	0.3202	0.1229	−0.1030	0.079*
H1B	0.1355	0.1347	−0.1968	0.079*
C2	0.2054 (6)	−0.0183 (3)	−0.1560 (5)	0.0717 (11)
H2C	0.2026	−0.0251	−0.2474	0.086*
H2D	0.3027	−0.0534	−0.0930	0.086*
C3	0.3212 (4)	0.1045 (3)	0.1340 (4)	0.0633 (9)
H3C	0.4166	0.1305	0.1234	0.076*
H3D	0.3052	0.1486	0.2019	0.076*
C4	0.3522 (5)	−0.0024 (3)	0.1854 (5)	0.0775 (13)
H4A	0.4158	0.0004	0.2835	0.093*
H4B	0.4174	−0.0376	0.1446	0.093*
C5	0.1144 (4)	0.2271 (3)	−0.0080 (4)	0.0623 (9)
H5A	0.0976	0.2407	0.0747	0.075*
H5B	0.0086	0.2285	−0.0837	0.075*
C6	0.2115 (5)	0.3185 (3)	−0.0272 (4)	0.0701 (10)
H6A	0.2455	0.3015	−0.1001	0.084*
H6B	0.1433	0.3810	−0.0545	0.084*
Cl	−0.2791 (7)	0.3491 (5)	0.0071 (5)	0.0512 (11)	0.50
O2	−0.3952 (13)	0.4190 (7)	0.0207 (17)	0.068 (3)	0.50
O3	−0.1755 (11)	0.3094 (7)	0.1357 (6)	0.079 (3)	0.50
O4	−0.3545 (12)	0.2592 (6)	−0.0712 (11)	0.117 (4)	0.50
O5	−0.1852 (10)	0.4025 (6)	−0.0511 (10)	0.111 (3)	0.50
Cl'	−0.2914 (8)	0.3279 (5)	0.0128 (6)	0.0567 (14)	0.50
O2'	−0.4037 (18)	0.4124 (10)	−0.0151 (19)	0.111 (6)	0.50
O3'	−0.3515 (17)	0.2410 (8)	0.0609 (19)	0.205 (6)	0.50
O4'	−0.2909 (14)	0.2925 (11)	−0.1112 (8)	0.122 (4)	0.50
O5'	−0.1399 (12)	0.3495 (13)	0.1173 (15)	0.201 (9)	0.50
H1	0.417 (3)	0.372 (4)	0.075 (2)	0.110 (18)*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Ni	0.0295 (3)	0.0379 (3)	0.0331 (3)	0.00180 (19)	0.01355 (19)	−0.00067 (19)
O1	0.0707 (16)	0.0752 (17)	0.0666 (16)	−0.0282 (14)	0.0316 (14)	−0.0081 (13)
N1	0.0337 (12)	0.0455 (13)	0.0412 (13)	−0.0011 (10)	0.0160 (10)	0.0023 (10)
N2	0.0505 (15)	0.0484 (14)	0.0488 (14)	0.0003 (11)	0.0254 (12)	−0.0096 (11)
N3	0.0412 (13)	0.0450 (14)	0.0458 (13)	0.0047 (11)	0.0146 (11)	0.0041 (11)
C1	0.078 (2)	0.077 (2)	0.062 (2)	−0.019 (2)	0.0470 (19)	−0.0085 (18)
C2	0.091 (3)	0.068 (2)	0.087 (3)	−0.009 (2)	0.068 (3)	−0.0165 (19)
C3	0.0449 (17)	0.074 (2)	0.056 (2)	−0.0156 (17)	0.0050 (15)	0.0099 (17)
C4	0.050 (2)	0.068 (2)	0.082 (3)	−0.0069 (18)	−0.0062 (19)	0.020 (2)
C5	0.0443 (17)	0.0475 (18)	0.092 (3)	−0.0049 (14)	0.0243 (17)	−0.0018 (17)
C6	0.065 (2)	0.053 (2)	0.084 (3)	−0.0085 (18)	0.021 (2)	0.0076 (19)
Cl	0.063 (2)	0.0437 (17)	0.0414 (17)	0.0168 (12)	0.0157 (13)	−0.0030 (12)
O2	0.078 (5)	0.041 (4)	0.115 (8)	0.010 (3)	0.071 (5)	0.002 (4)
O3	0.100 (7)	0.084 (5)	0.037 (3)	0.031 (4)	0.011 (3)	0.008 (3)
O4	0.113 (7)	0.064 (5)	0.129 (8)	0.007 (4)	0.002 (5)	−0.066 (6)
O5	0.127 (6)	0.118 (6)	0.142 (6)	0.040 (5)	0.112 (6)	0.043 (5)
Cl'	0.062 (2)	0.055 (3)	0.063 (2)	0.0285 (16)	0.0362 (17)	0.0077 (15)
O2'	0.144 (9)	0.093 (7)	0.111 (9)	0.081 (7)	0.068 (6)	0.016 (5)
O3'	0.251 (15)	0.126 (8)	0.324 (15)	0.055 (9)	0.205 (14)	0.116 (10)
O4'	0.130 (8)	0.178 (11)	0.066 (4)	0.080 (7)	0.048 (5)	0.005 (5)
O5'	0.057 (5)	0.239 (17)	0.260 (18)	−0.032 (8)	0.016 (8)	−0.146 (13)

Geometric parameters (Å, º)

Ni—N2	2.122 (2)	C1—C2	1.492 (5)
Ni—N2^i	2.122 (2)	C3—C4	1.441 (5)
Ni—N3	2.129 (2)	C5—C6	1.512 (5)
Ni—N3^i	2.129 (2)	Cl—O3	1.404 (4)
Ni—N1^i	2.191 (2)	Cl—O5	1.409 (5)
Ni—N1	2.191 (2)	Cl—O4	1.410 (4)
O1—C6	1.395 (5)	Cl—O2	1.422 (5)
N1—C1	1.472 (4)	Cl'—O5'	1.398 (5)
N1—C3	1.480 (4)	Cl'—O4'	1.400 (5)
N1—C5	1.490 (4)	Cl'—O3'	1.410 (5)
N2—C2	1.462 (4)	Cl'—O2'	1.417 (5)
N3—C4	1.475 (4)
N2—Ni—N2^i	180.00 (16)	C2—N2—Ni	110.11 (19)
N2—Ni—N3	91.17 (10)	C4—N3—Ni	110.69 (18)
N2^i—Ni—N3	88.83 (10)	N1—C1—C2	113.8 (3)
N2—Ni—N3^i	88.83 (10)	N2—C2—C1	112.4 (3)
N2^i—Ni—N3^i	91.17 (10)	C4—C3—N1	115.3 (3)
N3—Ni—N3^i	180.00 (16)	C3—C4—N3	115.4 (3)
N2—Ni—N1^i	97.68 (9)	N1—C5—C6	119.0 (3)
N2^i—Ni—N1^i	82.32 (9)	O1—C6—C5	111.9 (3)
N3—Ni—N1^i	98.18 (9)	O3—Cl—O5	108.7 (6)
N3^i—Ni—N1^i	81.82 (9)	O3—Cl—O4	105.3 (7)
N2—Ni—N1	82.32 (9)	O5—Cl—O4	110.8 (7)
N2^i—Ni—N1	97.68 (9)	O3—Cl—O2	110.3 (8)
N3—Ni—N1	81.82 (9)	O5—Cl—O2	110.4 (6)
N3^i—Ni—N1	98.18 (9)	O4—Cl—O2	111.2 (8)
N1^i—Ni—N1	180.00 (12)	O5'—Cl'—O4'	116.1 (10)
C1—N1—C3	114.3 (3)	O5'—Cl'—O3'	104.9 (9)
C1—N1—C5	108.9 (3)	O4'—Cl'—O3'	104.2 (8)
C3—N1—C5	109.5 (3)	O5'—Cl'—O2'	114.0 (11)
C1—N1—Ni	106.50 (19)	O4'—Cl'—O2'	108.5 (9)
C3—N1—Ni	106.47 (18)	O3'—Cl'—O2'	108.3 (9)
C5—N1—Ni	111.06 (17)
N2—Ni—N1—C1	12.6 (2)	N2—Ni—N3—C4	82.5 (3)
N2^i—Ni—N1—C1	−167.4 (2)	N2^i—Ni—N3—C4	−97.5 (3)
N3—Ni—N1—C1	104.9 (2)	N3^i—Ni—N3—C4	85 (96)
N3^i—Ni—N1—C1	−75.1 (2)	N1^i—Ni—N3—C4	−179.6 (3)
N1^i—Ni—N1—C1	−104 (22)	N1—Ni—N3—C4	0.4 (3)
N2—Ni—N1—C3	−109.8 (2)	C3—N1—C1—C2	83.5 (4)
N2^i—Ni—N1—C3	70.2 (2)	C5—N1—C1—C2	−153.6 (3)
N3—Ni—N1—C3	−17.5 (2)	Ni—N1—C1—C2	−33.8 (4)
N3^i—Ni—N1—C3	162.5 (2)	Ni—N2—C2—C1	−31.3 (4)
N1^i—Ni—N1—C3	134 (21)	N1—C1—C2—N2	45.1 (5)
N2—Ni—N1—C5	131.0 (2)	C1—N1—C3—C4	−83.8 (4)
N2^i—Ni—N1—C5	−49.0 (2)	C5—N1—C3—C4	153.7 (4)
N3—Ni—N1—C5	−136.6 (2)	Ni—N1—C3—C4	33.5 (4)
N3^i—Ni—N1—C5	43.4 (2)	N1—C3—C4—N3	−36.1 (5)
N1^i—Ni—N1—C5	15 (21)	Ni—N3—C4—C3	18.3 (5)
N2^i—Ni—N2—C2	104 (98)	C1—N1—C5—C6	−55.0 (4)
N3—Ni—N2—C2	−71.7 (3)	C3—N1—C5—C6	70.7 (4)
N3^i—Ni—N2—C2	108.3 (3)	Ni—N1—C5—C6	−172.0 (3)
N1^i—Ni—N2—C2	−170.1 (2)	N1—C5—C6—O1	−73.1 (5)
N1—Ni—N2—C2	9.9 (2)

Symmetry code: (i) −x, −y, −z.

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
O1—H1···O2^ii	0.82 (3)	2.09 (3)	2.895 (14)	168 (5)
O1—H1···O2′^ii	0.82 (3)	2.25 (3)	3.041 (18)	162 (4)
N2—H2A···O3^i	0.90	2.29	3.156 (9)	161
N3—H3A···O1^iii	0.90	2.28	3.113 (4)	155
N3—H3B···O4^i	0.90	2.25	3.089 (10)	155
N3—H3B···O4′^i	0.90	2.15	3.038 (14)	171

Symmetry codes: (i) −x, −y, −z; (ii) x+1, y, z; (iii) −x+1/2, y−1/2, −z+1/2.