Studies on α-nickel sulfate hexahydrate (NSH) crystals grown under different conditions are undertaken to investigate how changes in growth conditions affect crystal properties and whether or not there is any modification of the average crystal structure due to changes in crystallization conditions. Thermogravimetric and microhardness studies were carried out on the crystals grown from two different aqueous solutions, one of them containing an excess of sulfuric acid. Raman spectra were recorded and a single-crystal neutron diffraction investigation was conducted on both crystals. A detailed comparison between the two crystal structures and their Raman spectra showed that, although the two crystal structures are very similar, there are slight differences, such as the change in unit-cell volume, differences in the ionic structure, particularly of the sulfate ions, and changes in the hydrogen-bonding network. During solution crystal growth of a salt like NSH, varying the ionic environment around the solute ions influences the interionic interactions between them. Hence it is suggested that the above-mentioned structural differences result from a fine-tuning of the interionic interaction between the cations and anions of NSH in the solution phase. This difference is finally carried over to the crystalline phase. The resulting small crystal structure differences are enough to produce measurable changes in the thermal stability and fragility of the crystals. These differences in crystal properties can be explained on the basis of the observed structural differences between the two crystals grown under different conditions.
Supporting information
CCDC references: 1958605; 1963870
For both structures, data collection: SCAD; cell refinement: REFINE; data reduction: DATRED; program(s) used to refine structure: SHELXL2014/7 (Sheldrick, 2014); molecular graphics: ORTEP; software used to prepare material for publication: SHELX.
Crystal data top
H12NiO6·O4S | Dx = 2.083 Mg m−3 |
Mr = 263.09 | Neutron radiation, λ = 0.995 Å |
Tetragonal, P41212 | Cell parameters from 50 reflections |
a = 6.775 (2) Å | θ = 4–40° |
c = 18.275 (4) Å | µ = 0.23 mm−1 |
V = 838.8 (5) Å3 | T = 300 K |
Z = 4 | Cubic, blue |
F(000) = 105 | 3 × 3 × 3 mm |
Data collection top
Four circle diffractometer | Rint = 0.000 |
Radiation source: Dhruva reactor | θmax = 43.3°, θmin = 4.5° |
τ–\2t scans | h = 0→9 |
Absorption correction: integration datred | k = −9→0 |
| l = 0→25 |
743 measured reflections | 2 standard reflections every 20 reflections |
743 independent reflections | intensity decay: <3 |
467 reflections with I > 2σ(I) | |
Refinement top
Refinement on F2 | All H-atom parameters refined |
Least-squares matrix: full | w = 1/[σ2(Fo2) + (0.1313P)2 + 27.9835P] where P = (Fo2 + 2Fc2)/3 |
R[F2 > 2σ(F2)] = 0.082 | (Δ/σ)max < 0.001 |
wR(F2) = 0.295 | Δρmax = 1.33 e Å−3 |
S = 1.18 | Δρmin = −1.72 e Å−3 |
743 reflections | Extinction correction: SHELXL-2014/7 (Sheldrick 2014, Fc*=kFc[1+0.001xFc2λ3/sin(2θ)]-1/4 |
111 parameters | Extinction coefficient: 0.13 (2) |
0 restraints | Absolute structure: All f" are zero, so absolute structure could not be determined |
Hydrogen site location: difference Fourier map | |
Special details top
Geometry. All esds (except the esd in the dihedral angle between two l.s. planes)
are estimated using the full covariance matrix. The cell esds are taken
into account individually in the estimation of esds in distances, angles
and torsion angles; correlations between esds in cell parameters are only
used when they are defined by crystal symmetry. An approximate (isotropic)
treatment of cell esds is used for estimating esds involving l.s. planes. |
Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2) top | x | y | z | Uiso*/Ueq | |
Ni | 0.2111 (5) | 0.2111 (5) | 0.0000 | 0.0119 (11) | |
O1 | 0.1716 (12) | −0.0478 (12) | 0.0530 (4) | 0.0253 (18) | |
O2 | 0.4717 (11) | 0.2438 (11) | 0.0563 (3) | 0.0197 (16) | |
O3 | 0.0641 (11) | 0.3564 (11) | 0.0848 (3) | 0.0195 (15) | |
H11 | 0.080 (2) | −0.142 (2) | 0.0405 (8) | 0.036 (3) | |
H12 | 0.249 (3) | −0.081 (2) | 0.0941 (7) | 0.038 (3) | |
H21 | 0.565 (2) | 0.146 (3) | 0.0469 (10) | 0.044 (3) | |
H22 | 0.533 (3) | 0.375 (2) | 0.0592 (9) | 0.039 (3) | |
H31 | −0.013 (2) | 0.463 (2) | 0.0660 (8) | 0.038 (3) | |
H32 | −0.0171 (19) | 0.274 (2) | 0.1176 (7) | 0.029 (3) | |
S | 0.707 (2) | 0.707 (2) | 0.0000 | 0.015 (3) | |
O4 | 0.6208 (15) | 0.6209 (13) | 0.0659 (4) | 0.0312 (18) | |
O5 | 0.9216 (11) | 0.6727 (11) | 0.0003 (5) | 0.0266 (16) | |
Atomic displacement parameters (Å2) top | U11 | U22 | U33 | U12 | U13 | U23 |
Ni | 0.0131 (13) | 0.0131 (13) | 0.0096 (16) | −0.0008 (16) | −0.0005 (10) | 0.0005 (10) |
O1 | 0.034 (4) | 0.020 (3) | 0.022 (3) | −0.008 (3) | −0.011 (3) | 0.008 (3) |
O2 | 0.015 (3) | 0.020 (3) | 0.023 (3) | −0.002 (3) | −0.003 (2) | −0.003 (3) |
O3 | 0.023 (3) | 0.022 (3) | 0.014 (2) | 0.003 (3) | −0.002 (2) | −0.003 (3) |
H11 | 0.040 (7) | 0.024 (6) | 0.043 (6) | −0.006 (6) | −0.005 (6) | −0.001 (5) |
H12 | 0.045 (8) | 0.039 (8) | 0.032 (6) | 0.000 (6) | −0.010 (6) | 0.012 (5) |
H21 | 0.022 (6) | 0.047 (8) | 0.061 (9) | 0.005 (7) | −0.003 (6) | 0.002 (8) |
H22 | 0.045 (8) | 0.026 (6) | 0.045 (7) | −0.006 (6) | 0.000 (6) | −0.005 (6) |
H31 | 0.042 (8) | 0.031 (7) | 0.041 (6) | 0.014 (6) | 0.002 (6) | 0.002 (6) |
H32 | 0.025 (5) | 0.034 (7) | 0.028 (5) | 0.002 (5) | 0.002 (4) | −0.005 (5) |
S | 0.013 (4) | 0.013 (4) | 0.018 (6) | 0.001 (6) | 0.002 (4) | −0.002 (4) |
O4 | 0.047 (5) | 0.025 (4) | 0.021 (3) | −0.010 (3) | 0.006 (3) | 0.002 (3) |
O5 | 0.019 (3) | 0.020 (3) | 0.041 (4) | 0.005 (2) | −0.007 (3) | −0.004 (3) |
Geometric parameters (Å, º) top
Ni—O1 | 2.021 (8) | O2—H21 | 0.93 (2) |
Ni—O1i | 2.021 (8) | O2—H22 | 0.981 (16) |
Ni—O2 | 2.055 (7) | O3—H31 | 0.955 (15) |
Ni—O2i | 2.055 (7) | O3—H32 | 0.988 (16) |
Ni—O3i | 2.088 (6) | S—O4 | 1.460 (12) |
Ni—O3 | 2.088 (6) | S—O4i | 1.460 (12) |
O1—H11 | 0.917 (17) | S—O5i | 1.473 (13) |
O1—H12 | 0.944 (14) | S—O5 | 1.473 (13) |
| | | |
O1—Ni—O1i | 90.0 (5) | Ni—O1—H11 | 124.9 (11) |
O1—Ni—O2 | 88.1 (3) | Ni—O1—H12 | 121.0 (12) |
O1i—Ni—O2 | 178.1 (4) | H11—O1—H12 | 114.1 (15) |
O1—Ni—O2i | 178.1 (4) | Ni—O2—H21 | 114.4 (11) |
O1i—Ni—O2i | 88.1 (3) | Ni—O2—H22 | 119.3 (12) |
O2—Ni—O2i | 93.8 (4) | H21—O2—H22 | 111.6 (16) |
O1—Ni—O3i | 90.2 (3) | Ni—O3—H31 | 110.6 (10) |
O1i—Ni—O3i | 89.4 (3) | Ni—O3—H32 | 116.6 (9) |
O2—Ni—O3i | 91.0 (3) | H31—O3—H32 | 110.1 (14) |
O2i—Ni—O3i | 89.3 (3) | O4—S—O4i | 111.2 (14) |
O1—Ni—O3 | 89.4 (3) | O4—S—O5i | 109.5 (5) |
O1i—Ni—O3 | 90.3 (3) | O4i—S—O5i | 109.2 (5) |
O2—Ni—O3 | 89.3 (3) | O4—S—O5 | 109.2 (5) |
O2i—Ni—O3 | 91.0 (3) | O4i—S—O5 | 109.5 (5) |
O3i—Ni—O3 | 179.6 (5) | O5i—S—O5 | 108.1 (13) |
Symmetry code: (i) y, x, −z. |
Hydrogen-bond geometry (Å, º) top
D—H···A | D—H | H···A | D···A | D—H···A |
O1—H11···O5ii | 0.917 (17) | 1.810 (16) | 2.717 (11) | 169.8 (16) |
O1—H11···Sii | 0.917 (17) | 2.83 (2) | 3.690 (19) | 157.1 (13) |
O1—H12···O3iii | 0.944 (14) | 1.862 (15) | 2.799 (10) | 171.1 (17) |
O2—H21···O5iv | 0.93 (2) | 1.892 (19) | 2.773 (11) | 156.5 (15) |
O2—H22···O4 | 0.981 (16) | 1.775 (17) | 2.753 (11) | 174.4 (18) |
O2—H22···S | 0.981 (16) | 2.76 (2) | 3.666 (19) | 153.7 (12) |
O3—H31···O5v | 0.955 (15) | 1.912 (16) | 2.812 (10) | 156.1 (14) |
O3—H31···Sv | 0.955 (15) | 2.791 (15) | 3.728 (7) | 167.0 (15) |
O3—H32···O4iii | 0.988 (16) | 1.744 (16) | 2.722 (12) | 169.6 (13) |
O3—H32···Siii | 0.988 (16) | 2.777 (13) | 3.676 (8) | 151.5 (10) |
Symmetry codes: (ii) x−1, y−1, z; (iii) −x+1/2, y−1/2, −z+1/4; (iv) y, x−1, −z; (v) x−1, y, z. |
Crystal data top
H12NiO6·O4S | Dx = 2.077 Mg m−3 |
Mr = 263.09 | Neutron radiation, λ = 0.995 Å |
Tetragonal, P41212 | Cell parameters from 50 reflections |
a = 6.785 (2) Å | θ = 4–40° |
c = 18.279 (5) Å | µ = 0.23 mm−1 |
V = 841.5 (5) Å3 | T = 300 K |
Z = 4 | Cubic, blue |
F(000) = 105 | 3 × 3 × 3 mm |
Data collection top
Four circle diffractometer | Rint = 0.007 |
Radiation source: Dhruva reactor | θmax = 43.3°, θmin = 4.5° |
τ–\2t scans | h = 0→9 |
Absorption correction: integration datred | k = −8→0 |
| l = 0→25 |
745 measured reflections | 2 standard reflections every 20 reflections |
744 independent reflections | intensity decay: <3 |
471 reflections with I > 2σ(I) | |
Refinement top
Refinement on F2 | All H-atom parameters refined |
Least-squares matrix: full | w = 1/[σ2(Fo2) + (0.1174P)2 + 4.1936P] where P = (Fo2 + 2Fc2)/3 |
R[F2 > 2σ(F2)] = 0.070 | (Δ/σ)max < 0.001 |
wR(F2) = 0.245 | Δρmax = 1.22 e Å−3 |
S = 1.25 | Δρmin = −1.30 e Å−3 |
744 reflections | Extinction correction: SHELXL-2014/7 (Sheldrick 2014, Fc*=kFc[1+0.001xFc2λ3/sin(2θ)]-1/4 |
111 parameters | Extinction coefficient: 0.19 (3) |
0 restraints | Absolute structure: All f" are zero, so absolute structure could not be determined |
Hydrogen site location: difference Fourier map | |
Special details top
Geometry. All esds (except the esd in the dihedral angle between two l.s. planes)
are estimated using the full covariance matrix. The cell esds are taken
into account individually in the estimation of esds in distances, angles
and torsion angles; correlations between esds in cell parameters are only
used when they are defined by crystal symmetry. An approximate (isotropic)
treatment of cell esds is used for estimating esds involving l.s. planes. |
Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2) top | x | y | z | Uiso*/Ueq | |
Ni | 0.2103 (4) | 0.2103 (4) | 0.0000 | 0.0137 (9) | |
O1 | 0.1734 (11) | −0.0480 (11) | 0.0529 (3) | 0.0276 (15) | |
O2 | 0.4722 (9) | 0.2447 (9) | 0.0561 (3) | 0.0197 (13) | |
O3 | 0.0650 (9) | 0.3556 (9) | 0.0849 (3) | 0.0197 (13) | |
H11 | 0.0799 (19) | −0.1428 (18) | 0.0412 (8) | 0.038 (3) | |
H12 | 0.248 (2) | −0.081 (2) | 0.0953 (6) | 0.042 (3) | |
H21 | 0.5681 (19) | 0.145 (2) | 0.0476 (8) | 0.041 (3) | |
H22 | 0.535 (2) | 0.3732 (18) | 0.0593 (7) | 0.035 (3) | |
H31 | −0.0139 (19) | 0.4650 (18) | 0.0659 (7) | 0.038 (3) | |
H32 | −0.0139 (19) | 0.2711 (18) | 0.1168 (6) | 0.032 (2) | |
S | 0.7083 (17) | 0.7083 (17) | 0.0000 | 0.016 (2) | |
O4 | 0.6208 (13) | 0.6204 (11) | 0.0659 (3) | 0.0309 (15) | |
O5 | 0.9227 (9) | 0.6731 (10) | 0.0005 (4) | 0.0268 (13) | |
Atomic displacement parameters (Å2) top | U11 | U22 | U33 | U12 | U13 | U23 |
Ni | 0.0139 (12) | 0.0139 (12) | 0.0134 (15) | −0.0014 (14) | −0.0009 (9) | 0.0009 (9) |
O1 | 0.033 (3) | 0.027 (3) | 0.023 (3) | −0.007 (3) | −0.008 (3) | 0.006 (2) |
O2 | 0.018 (3) | 0.018 (3) | 0.023 (2) | −0.003 (3) | −0.0027 (19) | −0.002 (2) |
O3 | 0.025 (3) | 0.020 (3) | 0.0142 (19) | 0.004 (2) | −0.002 (2) | −0.002 (2) |
H11 | 0.035 (6) | 0.028 (5) | 0.052 (6) | −0.003 (5) | 0.002 (5) | 0.001 (5) |
H12 | 0.053 (7) | 0.041 (7) | 0.033 (5) | 0.002 (5) | −0.011 (5) | 0.008 (5) |
H21 | 0.027 (5) | 0.040 (6) | 0.058 (7) | 0.005 (5) | −0.006 (5) | −0.002 (6) |
H22 | 0.039 (6) | 0.022 (5) | 0.045 (6) | −0.007 (5) | −0.003 (5) | −0.004 (4) |
H31 | 0.039 (6) | 0.034 (6) | 0.043 (5) | 0.013 (5) | −0.002 (5) | 0.002 (5) |
H32 | 0.033 (5) | 0.033 (6) | 0.029 (5) | 0.003 (5) | 0.001 (4) | 0.001 (4) |
S | 0.016 (4) | 0.016 (4) | 0.017 (5) | 0.003 (5) | 0.002 (3) | −0.002 (3) |
O4 | 0.048 (4) | 0.020 (3) | 0.024 (2) | −0.010 (3) | 0.006 (3) | 0.001 (2) |
O5 | 0.017 (3) | 0.022 (3) | 0.041 (3) | 0.0042 (17) | −0.001 (3) | −0.004 (3) |
Geometric parameters (Å, º) top
Ni—O1i | 2.017 (7) | O2—H21 | 0.953 (15) |
Ni—O1 | 2.017 (7) | O2—H22 | 0.973 (12) |
Ni—O2 | 2.065 (6) | O3—H31 | 0.979 (13) |
Ni—O2i | 2.065 (6) | O3—H32 | 0.978 (14) |
Ni—O3i | 2.085 (5) | S—O4 | 1.469 (11) |
Ni—O3 | 2.085 (5) | S—O4i | 1.469 (11) |
O1—H11 | 0.928 (16) | S—O5i | 1.474 (11) |
O1—H12 | 0.954 (13) | S—O5 | 1.474 (11) |
| | | |
O1i—Ni—O1 | 90.8 (4) | Ni—O1—H11 | 125.2 (10) |
O1i—Ni—O2 | 178.7 (3) | Ni—O1—H12 | 121.9 (10) |
O1—Ni—O2 | 88.1 (2) | H11—O1—H12 | 112.8 (13) |
O1i—Ni—O2i | 88.1 (2) | Ni—O2—H21 | 115.2 (9) |
O1—Ni—O2i | 178.7 (3) | Ni—O2—H22 | 120.6 (9) |
O2—Ni—O2i | 93.0 (4) | H21—O2—H22 | 110.4 (13) |
O1i—Ni—O3i | 89.7 (3) | Ni—O3—H31 | 110.7 (8) |
O1—Ni—O3i | 90.3 (3) | Ni—O3—H32 | 115.2 (8) |
O2—Ni—O3i | 90.9 (2) | H31—O3—H32 | 110.9 (12) |
O2i—Ni—O3i | 89.1 (2) | O4—S—O4i | 110.2 (12) |
O1i—Ni—O3 | 90.3 (3) | O4—S—O5i | 109.9 (4) |
O1—Ni—O3 | 89.7 (3) | O4i—S—O5i | 109.2 (4) |
O2—Ni—O3 | 89.1 (2) | O4—S—O5 | 109.2 (4) |
O2i—Ni—O3 | 90.9 (2) | O4i—S—O5 | 109.9 (4) |
O3i—Ni—O3 | 180.0 (5) | O5i—S—O5 | 108.6 (12) |
Symmetry code: (i) y, x, −z. |
Hydrogen-bond geometry (Å, º) top
D—H···A | D—H | H···A | D···A | D—H···A |
O1—H11···O5ii | 0.928 (16) | 1.804 (15) | 2.719 (10) | 168.2 (14) |
O1—H11···Sii | 0.928 (16) | 2.82 (2) | 3.691 (17) | 157.1 (11) |
O1—H12···O3iii | 0.954 (13) | 1.848 (14) | 2.791 (8) | 168.9 (15) |
O2—H21···O5iv | 0.953 (15) | 1.884 (15) | 2.775 (9) | 154.6 (12) |
O2—H22···O4 | 0.973 (12) | 1.779 (13) | 2.747 (9) | 173.0 (14) |
O2—H22···S | 0.973 (12) | 2.779 (19) | 3.676 (16) | 153.6 (10) |
O3—H31···O5v | 0.979 (13) | 1.899 (13) | 2.820 (9) | 155.6 (12) |
O3—H31···Sv | 0.979 (13) | 2.780 (12) | 3.741 (5) | 167.1 (12) |
O3—H32···O4iii | 0.978 (14) | 1.757 (14) | 2.725 (10) | 170.3 (11) |
O3—H32···Siii | 0.978 (14) | 2.802 (12) | 3.681 (7) | 150.0 (9) |
Symmetry codes: (ii) x−1, y−1, z; (iii) −x+1/2, y−1/2, −z+1/4; (iv) y, x−1, −z; (v) x−1, y, z. |