1,6-Bis(diphenyl­arsino)hexa­ne

Shawkataly, O. bin; Khan, I.A.; Goh, J.H.; Fun, H.-K.

doi:10.1107/S1600536809036757

organic compounds

CRYSTALLOGRAPHIC
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ISSN: 2056-9890

Volume 65| Part 10| October 2009| Pages o2591-o2592

doi:10.1107/S1600536809036757

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1,6-Bis(diphenylarsino)hexane

Omar bin Shawkataly,^a ^*‡ Imthyaz Ahmed Khan,^a Jia Hao Goh ^b and Hoong-Kun Fun ^b §

^aChemical Sciences Programme, Centre for Distance Education, Universiti Sains Malaysia, 11800 USM, Penang, Malaysia, and ^bX-ray Crystallography Unit, School of Physics, Universiti Sains Malaysia, 11800 USM, Penang, Malaysia
^*Correspondence e-mail: omarsa@usm.my

(Received 8 September 2009; accepted 11 September 2009; online 30 September 2009)

The title diphenylarsino compound, C₃₀H₃₂As₂ or Ph₂As(CH₂)₆AsPh₂, lies about a crystallographic inversion centre located at the mid-point of the central Csp³—Csp³ bond of the methylene chain. The two benzene rings bonded to As are inclined to one another at a dihedral angle of 75.98 (8)°. In the crystal structure, weak intermolecular C—H⋯π interactions stack the molecules down the b axis.

Related literature

For general background to and applications of diphenylarsino derivatives, see: Hill et al. (1983 ); Song et al. (2005 ). For the preparation of the title compound, see: Aguiar & Archibald (1967 ); Burfield et al. (1977 , 1978 ); Tzschach & Lange (1962 ). For closely related structures, see: Hill et al. (2001 ); Shawkataly et al. (2005 ). For information on the Cambridge Structural Database, see: Allen (2002 ). For bond-length data, see: Allen et al. (1987 ). For the stability of the temperature controller used for the data collection, see: Cosier & Glazer (1986 ).

Experimental

Crystal data

C₃₀H₃₂As₂
M_r = 542.40
Monoclinic, P 2₁ /c
a = 12.3774 (2) Å
b = 5.7145 (1) Å
c = 18.1263 (3) Å
β = 101.076 (1)°
V = 1258.20 (4) Å³
Z = 2
Mo Kα radiation
μ = 2.67 mm⁻¹
T = 100 K
0.44 × 0.29 × 0.03 mm

Data collection

Bruker SMART APEXII CCD area-detector diffractometer
Absorption correction: multi-scan (SADABS; Bruker, 2005 ) T_min = 0.384, T_max = 0.919
24043 measured reflections
5572 independent reflections
4144 reflections with I > 2σ(I)
R_int = 0.052

Refinement

R[F² > 2σ(F²)] = 0.035
wR(F²) = 0.084
S = 1.03
5572 reflections
209 parameters
All H-atom parameters refined
Δρ_max = 0.58 e Å⁻³
Δρ_min = −0.47 e Å⁻³

Table 1
Hydrogen-bond geometry (Å, °)

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
C15—H15B⋯Cg1ⁱ	0.97 (3)	2.81 (3)	3.776 (2)	169.9 (18)
C4—H4⋯Cg2ⁱⁱ	0.91 (2)	2.80 (2)	3.708 (2)	173.2 (19)
C9—H9⋯Cg2ⁱⁱⁱ	0.91 (2)	2.97 (2)	3.617 (2)	129.5 (16)
Symmetry codes: (i) $[-x+1, y-{\script{1\over 2}}, -z+{\script{1\over 2}}]$ ; (ii) $[x, -y+{\script{1\over 2}}, z-{\script{3\over 2}}]$ ; (iii) $[-x, y-{\script{1\over 2}}, -z+{\script{1\over 2}}]$ . Cg1 and Cg2 are the centroids of the C1–C6 and C7–C12 benzene rings, respectively.

Data collection: APEX2 (Bruker, 2005); cell refinement: SAINT (Bruker, 2005); data reduction: SAINT; program(s) used to solve structure: SHELXTL (Sheldrick, 2008 ); program(s) used to refine structure: SHELXTL molecular graphics: SHELXTL; software used to prepare material for publication: SHELXTL and PLATON (Spek, 2009 ).

Supporting information

Crystal structure: contains datablocks global, I. DOI: 10.1107/S1600536809036757/sj2648sup1.cif

Structure factors: contains datablock I. DOI: 10.1107/S1600536809036757/sj2648Isup2.hkl

checkCIF report

Comment top

1,6-Bis(diphenylarsino)hexane has been used for trans chelation in transition metal complexes (Hill et al., 1983). A search of the November 2008 release of the Cambridge Structural Database (Allen, 2002) revealed no structures of complexes containing the above ligand. Among bis(diphenylarsino)alkanes, only the structure of 1,2-bis(diphenylarsino)ethane (Hill et al., 2001) and complexes of the ligand 1,3-bis(diphenylarsino)propane (Song et al., 2005) are known.

The title compound (Fig. 1), contains a crystallographic inversion centre at the mid-point of the central Csp³—Csp³ (C15—C15A) bond [symmetry code of atoms labellel with suffix A: -x+1, -y+1, -z+1]. The C1-C6 and C7-C12 benzene rings are inclined to one another, with a dihedral angle of 75.98 (8)°. The bond lengths (Allen et al., 1987) are comparable to those found in closely related structures (Hill et al., 2001; Shawkataly et al., 2005). In the crystal structure (Fig. 2), the molecules are stacked down the b axis. The crystal structure is consolidated by intermolecular C15—H15B···Cg1, C4—H4···Cg2 and C9—H9···Cg2 interactions (Table 1).

Related literature top

For general background to and applications of diphenylarsino derivatives, see: Hill et al. (1983); Song et al. (2005). For the preparation of the title compound, see: Aguiar & Archibald (1967); Burfield et al. (1977, 1978); Tzschach & Lange (1962). For closely related structures, see: Hill et al. (2001); Shawkataly et al. (2005). For information on the Cambridge Structural Database, see: Allen (2002). For bond-length data, see: Allen et al. (1987). For the stability of the temperature controller used for the data collection, see: Cosier & Glazer (1986).

Experimental top

Solvents were dried by recommended literature routes (Burfield et al., 1977, 1978) and the title compound was prepared by the reaction of diphenylarsino lithium with 1,6-dibromohexane in dry THF at 273 K under nitrogen atmosphere (Aguiar et al., 1967; Tzschach & Lange, 1962). Colourless plates of suitable quality for single crystal X-ray diffraction studies were obtained by slow evaporation from ethanol solution.

Computing details top

Data collection: APEX2 (Bruker, 2005); cell refinement: SAINT (Bruker, 2005); data reduction: SAINT (Bruker, 2005); program(s) used to solve structure: SHELXTL (Sheldrick, 2008); program(s) used to refine structure: SHELXTL (Sheldrick, 2008); molecular graphics: SHELXTL (Sheldrick, 2008); software used to prepare material for publication: SHELXTL (Sheldrick, 2008) and PLATON (Spek, 2009).

Figures top

	Fig. 1. The molecular structure of the title compound, showing 50% probability displacement ellipsoids for non-H atoms and the atom-numbering scheme. The suffix A corresponds to the symmetry code [-x+1, -y+1, -z+1].
	Fig. 2. The crystal structure of the title compound viewed along the b axis, showing stacking of molecules along the b axis.

1,6-Bis(diphenylarsino)hexane top

Crystal data top

C₃₀H₃₂As₂	F(000) = 556
M_r = 542.40	D_x = 1.432 Mg m⁻³
Monoclinic, P2₁/c	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ybc	Cell parameters from 5477 reflections
a = 12.3774 (2) Å	θ = 3.1–32.2°
b = 5.7145 (1) Å	µ = 2.67 mm⁻¹
c = 18.1263 (3) Å	T = 100 K
β = 101.076 (1)°	Plate, colourless
V = 1258.20 (4) Å³	0.44 × 0.29 × 0.03 mm
Z = 2

Data collection top

Bruker SMART APEXII CCD area-detector diffractometer	5572 independent reflections
Radiation source: fine-focus sealed tube	4144 reflections with I > 2σ(I)
Graphite monochromator	R_int = 0.052
ϕ and ω scans	θ_max = 35.1°, θ_min = 2.3°
Absorption correction: multi-scan (SADABS; Bruker, 2005)	h = −19→20
T_min = 0.384, T_max = 0.919	k = −9→8
24043 measured reflections	l = −29→26

Refinement top

Refinement on F²	Primary atom site location: structure-invariant direct methods
Least-squares matrix: full	Secondary atom site location: difference Fourier map
R[F² > 2σ(F²)] = 0.035	Hydrogen site location: inferred from neighbouring sites
wR(F²) = 0.084	All H-atom parameters refined
S = 1.03	w = 1/[σ²(F_o²) + (0.0344P)² + 0.3375P] where P = (F_o² + 2F_c²)/3
5572 reflections	(Δ/σ)_max = 0.001
209 parameters	Δρ_max = 0.58 e Å⁻³
0 restraints	Δρ_min = −0.47 e Å⁻³

Crystal data top

C₃₀H₃₂As₂	V = 1258.20 (4) Å³
M_r = 542.40	Z = 2
Monoclinic, P2₁/c	Mo Kα radiation
a = 12.3774 (2) Å	µ = 2.67 mm⁻¹
b = 5.7145 (1) Å	T = 100 K
c = 18.1263 (3) Å	0.44 × 0.29 × 0.03 mm
β = 101.076 (1)°

Data collection top

Bruker SMART APEXII CCD area-detector diffractometer	5572 independent reflections
Absorption correction: multi-scan (SADABS; Bruker, 2005)	4144 reflections with I > 2σ(I)
T_min = 0.384, T_max = 0.919	R_int = 0.052
24043 measured reflections

Refinement top

R[F² > 2σ(F²)] = 0.035	0 restraints
wR(F²) = 0.084	All H-atom parameters refined
S = 1.03	Δρ_max = 0.58 e Å⁻³
5572 reflections	Δρ_min = −0.47 e Å⁻³
209 parameters

Special details top

Experimental. The crystal was placed in the cold stream of an Oxford Cyrosystems Cobra open-flow nitrogen cryostat (Cosier & Glazer, 1986) operating at 100.0 (1)K.

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.

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 > 2sigma(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 (Å²) top

	x	y	z	U_iso*/U_eq
As1	0.351354 (13)	0.98218 (3)	0.284872 (8)	0.01668 (5)
C1	0.29473 (13)	0.8690 (3)	0.18275 (8)	0.0183 (3)
C2	0.32226 (14)	0.6566 (3)	0.15347 (9)	0.0226 (3)
C3	0.27896 (15)	0.5965 (4)	0.07878 (10)	0.0264 (4)
C4	0.20763 (15)	0.7469 (4)	0.03339 (10)	0.0299 (4)
C5	0.17979 (17)	0.9578 (4)	0.06212 (10)	0.0313 (4)
C6	0.22374 (16)	1.0190 (3)	0.13583 (10)	0.0257 (3)
C7	0.20975 (13)	0.9750 (3)	0.31860 (8)	0.0165 (3)
C8	0.13587 (13)	0.7891 (3)	0.30118 (9)	0.0192 (3)
C9	0.03431 (14)	0.7930 (3)	0.32299 (9)	0.0224 (3)
C10	0.00492 (14)	0.9838 (3)	0.36256 (9)	0.0225 (3)
C11	0.07749 (14)	1.1692 (3)	0.38019 (9)	0.0235 (3)
C12	0.17944 (14)	1.1653 (3)	0.35879 (9)	0.0208 (3)
C13	0.41464 (14)	0.6910 (3)	0.33284 (9)	0.0195 (3)
C14	0.43828 (15)	0.7124 (3)	0.41818 (9)	0.0218 (3)
C15	0.48951 (15)	0.4927 (3)	0.45720 (9)	0.0234 (3)
H2	0.3700 (19)	0.552 (4)	0.1820 (12)	0.026 (6)*
H3	0.303 (2)	0.458 (4)	0.0593 (13)	0.031 (6)*
H4	0.1799 (19)	0.704 (4)	−0.0149 (13)	0.040 (6)*
H5	0.128 (2)	1.066 (5)	0.0299 (15)	0.048 (7)*
H6	0.2055 (18)	1.172 (4)	0.1569 (12)	0.034 (6)*
H8	0.1550 (16)	0.654 (4)	0.2729 (11)	0.026 (5)*
H9	−0.0121 (17)	0.669 (4)	0.3102 (12)	0.033 (6)*
H10	−0.063 (2)	0.989 (4)	0.3763 (14)	0.033 (7)*
H11	0.0573 (18)	1.300 (4)	0.4072 (12)	0.036 (6)*
H12	0.2278 (16)	1.291 (4)	0.3710 (11)	0.024 (5)*
H13A	0.4768 (18)	0.668 (4)	0.3164 (12)	0.033 (6)*
H13B	0.364 (2)	0.570 (4)	0.3189 (13)	0.032 (6)*
H14A	0.370 (2)	0.752 (5)	0.4355 (13)	0.043 (7)*
H14B	0.4872 (17)	0.844 (4)	0.4344 (11)	0.026 (5)*
H15A	0.4390 (19)	0.362 (5)	0.4414 (13)	0.037 (6)*
H15B	0.556 (2)	0.465 (4)	0.4373 (14)	0.032 (6)*

Atomic displacement parameters (Å²) top

	U¹¹	U²²	U³³	U¹²	U¹³	U²³
As1	0.01574 (8)	0.01865 (8)	0.01533 (7)	−0.00094 (6)	0.00222 (5)	0.00114 (6)
C1	0.0172 (6)	0.0221 (7)	0.0160 (6)	−0.0017 (6)	0.0044 (5)	0.0026 (5)
C2	0.0218 (7)	0.0269 (8)	0.0194 (7)	0.0002 (7)	0.0050 (6)	0.0007 (6)
C3	0.0285 (9)	0.0296 (9)	0.0225 (8)	−0.0069 (7)	0.0087 (7)	−0.0053 (7)
C4	0.0283 (9)	0.0462 (11)	0.0147 (7)	−0.0115 (8)	0.0028 (6)	−0.0013 (7)
C5	0.0299 (9)	0.0430 (11)	0.0185 (7)	0.0012 (8)	−0.0011 (7)	0.0079 (7)
C6	0.0269 (8)	0.0299 (9)	0.0195 (7)	0.0042 (7)	0.0027 (6)	0.0046 (6)
C7	0.0169 (6)	0.0182 (7)	0.0137 (6)	0.0008 (5)	0.0014 (5)	0.0017 (5)
C8	0.0195 (7)	0.0187 (7)	0.0188 (7)	0.0003 (6)	0.0022 (5)	−0.0016 (5)
C9	0.0204 (7)	0.0243 (8)	0.0217 (7)	−0.0025 (6)	0.0018 (6)	−0.0010 (6)
C10	0.0173 (7)	0.0303 (9)	0.0198 (7)	0.0033 (6)	0.0035 (6)	0.0008 (6)
C11	0.0258 (8)	0.0243 (8)	0.0200 (7)	0.0046 (7)	0.0034 (6)	−0.0030 (6)
C12	0.0219 (7)	0.0195 (7)	0.0200 (7)	−0.0005 (6)	0.0013 (6)	−0.0013 (6)
C13	0.0186 (7)	0.0239 (8)	0.0156 (6)	0.0047 (6)	0.0022 (5)	0.0022 (6)
C14	0.0235 (8)	0.0263 (8)	0.0149 (6)	0.0071 (7)	0.0016 (6)	0.0015 (6)
C15	0.0250 (8)	0.0283 (9)	0.0154 (6)	0.0096 (7)	0.0003 (6)	0.0008 (6)

Geometric parameters (Å, º) top

As1—C1	1.9590 (15)	C8—H8	0.98 (2)
As1—C7	1.9644 (16)	C9—C10	1.391 (2)
As1—C13	1.9688 (16)	C9—H9	0.91 (2)
C1—C2	1.393 (2)	C10—C11	1.386 (3)
C1—C6	1.394 (2)	C10—H10	0.93 (3)
C2—C3	1.400 (2)	C11—C12	1.390 (2)
C2—H2	0.93 (2)	C11—H11	0.95 (2)
C3—C4	1.384 (3)	C12—H12	0.94 (2)
C3—H3	0.94 (2)	C13—C14	1.523 (2)
C4—C5	1.383 (3)	C13—H13A	0.89 (2)
C4—H4	0.91 (2)	C13—H13B	0.93 (3)
C5—C6	1.387 (3)	C14—C15	1.519 (2)
C5—H5	0.99 (3)	C14—H14A	0.98 (2)
C6—H6	0.99 (2)	C14—H14B	0.98 (2)
C7—C8	1.398 (2)	C15—C15ⁱ	1.525 (3)
C7—C12	1.399 (2)	C15—H15A	0.98 (3)
C8—C9	1.388 (2)	C15—H15B	0.97 (3)

C1—As1—C7	96.24 (6)	C10—C9—H9	121.6 (14)
C1—As1—C13	100.26 (7)	C11—C10—C9	119.72 (16)
C7—As1—C13	98.51 (7)	C11—C10—H10	119.9 (13)
C2—C1—C6	118.37 (15)	C9—C10—H10	120.4 (14)
C2—C1—As1	125.33 (12)	C10—C11—C12	120.41 (16)
C6—C1—As1	116.28 (13)	C10—C11—H11	119.8 (14)
C1—C2—C3	120.38 (17)	C12—C11—H11	119.8 (14)
C1—C2—H2	121.8 (14)	C11—C12—C7	120.44 (16)
C3—C2—H2	117.8 (14)	C11—C12—H12	119.7 (12)
C4—C3—C2	120.32 (18)	C7—C12—H12	119.9 (13)
C4—C3—H3	120.8 (14)	C14—C13—As1	111.29 (11)
C2—C3—H3	118.7 (15)	C14—C13—H13A	110.1 (14)
C5—C4—C3	119.60 (16)	As1—C13—H13A	105.9 (15)
C5—C4—H4	121.5 (16)	C14—C13—H13B	108.8 (15)
C3—C4—H4	118.9 (16)	As1—C13—H13B	108.4 (15)
C4—C5—C6	120.16 (18)	H13A—C13—H13B	112 (2)
C4—C5—H5	119.9 (16)	C15—C14—C13	112.84 (14)
C6—C5—H5	119.9 (16)	C15—C14—H14A	110.5 (15)
C5—C6—C1	121.15 (18)	C13—C14—H14A	109.6 (13)
C5—C6—H6	121.0 (13)	C15—C14—H14B	108.6 (12)
C1—C6—H6	117.9 (12)	C13—C14—H14B	110.8 (12)
C8—C7—C12	118.61 (15)	H14A—C14—H14B	104.2 (19)
C8—C7—As1	121.98 (12)	C14—C15—C15ⁱ	113.73 (18)
C12—C7—As1	119.36 (12)	C14—C15—H15A	107.9 (14)
C9—C8—C7	120.81 (15)	C15ⁱ—C15—H15A	108.3 (14)
C9—C8—H8	119.0 (12)	C14—C15—H15B	105.7 (14)
C7—C8—H8	120.2 (12)	C15ⁱ—C15—H15B	113.3 (15)
C8—C9—C10	120.01 (16)	H15A—C15—H15B	107.6 (19)
C8—C9—H9	118.4 (14)

C7—As1—C1—C2	−114.45 (14)	C1—As1—C7—C12	−134.94 (13)
C13—As1—C1—C2	−14.60 (15)	C13—As1—C7—C12	123.67 (13)
C7—As1—C1—C6	67.51 (14)	C12—C7—C8—C9	0.2 (2)
C13—As1—C1—C6	167.36 (13)	As1—C7—C8—C9	−177.24 (12)
C6—C1—C2—C3	−0.2 (2)	C7—C8—C9—C10	0.1 (2)
As1—C1—C2—C3	−178.21 (13)	C8—C9—C10—C11	−0.1 (2)
C1—C2—C3—C4	−0.5 (3)	C9—C10—C11—C12	−0.2 (3)
C2—C3—C4—C5	0.4 (3)	C10—C11—C12—C7	0.6 (2)
C3—C4—C5—C6	0.5 (3)	C8—C7—C12—C11	−0.6 (2)
C4—C5—C6—C1	−1.2 (3)	As1—C7—C12—C11	176.96 (12)
C2—C1—C6—C5	1.0 (3)	C1—As1—C13—C14	−165.02 (12)
As1—C1—C6—C5	179.24 (15)	C7—As1—C13—C14	−67.05 (13)
C1—As1—C7—C8	42.50 (13)	As1—C13—C14—C15	−178.78 (13)
C13—As1—C7—C8	−58.90 (13)	C13—C14—C15—C15ⁱ	−178.14 (19)

Symmetry code: (i) −x+1, −y+1, −z+1.

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
C15—H15B···Cg1ⁱⁱ	0.97 (3)	2.81 (3)	3.776 (2)	169.9 (18)
C4—H4···Cg2ⁱⁱⁱ	0.91 (2)	2.80 (2)	3.708 (2)	173.2 (19)
C9—H9···Cg2^iv	0.91 (2)	2.97 (2)	3.617 (2)	129.5 (16)

Symmetry codes: (ii) −x+1, y−1/2, −z+1/2; (iii) x, −y+1/2, z−3/2; (iv) −x, y−1/2, −z+1/2.

Experimental details

Crystal data
Chemical formula	C₃₀H₃₂As₂
M_r	542.40
Crystal system, space group	Monoclinic, P2₁/c
Temperature (K)	100
a, b, c (Å)	12.3774 (2), 5.7145 (1), 18.1263 (3)
β (°)	101.076 (1)
V (Å³)	1258.20 (4)
Z	2
Radiation type	Mo Kα
µ (mm⁻¹)	2.67
Crystal size (mm)	0.44 × 0.29 × 0.03

Data collection
Diffractometer	Bruker SMART APEXII CCD area-detector diffractometer
Absorption correction	Multi-scan (SADABS; Bruker, 2005)
T_min, T_max	0.384, 0.919
No. of measured, independent and observed [I > 2σ(I)] reflections	24043, 5572, 4144
R_int	0.052
(sin θ/λ)_max (Å⁻¹)	0.809

Refinement
R[F² > 2σ(F²)], wR(F²), S	0.035, 0.084, 1.03
No. of reflections	5572
No. of parameters	209
H-atom treatment	All H-atom parameters refined
Δρ_max, Δρ_min (e Å⁻³)	0.58, −0.47

Computer programs: APEX2 (Bruker, 2005), SAINT (Bruker, 2005), SHELXTL (Sheldrick, 2008) and PLATON (Spek, 2009).

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
C15—H15B···Cg1ⁱ	0.97 (3)	2.81 (3)	3.776 (2)	169.9 (18)
C4—H4···Cg2ⁱⁱ	0.91 (2)	2.80 (2)	3.708 (2)	173.2 (19)
C9—H9···Cg2ⁱⁱⁱ	0.91 (2)	2.97 (2)	3.617 (2)	129.5 (16)

Symmetry codes: (i) −x+1, y−1/2, −z+1/2; (ii) x, −y+1/2, z−3/2; (iii) −x, y−1/2, −z+1/2.

Footnotes

‡On secondment to: Multimedia University, Melaka Campus, Jalan Ayer Keroh Lama, 74750 Melaka, Malaysia.

§Thomson Reuters ResearcherID: A-3561-2009.

Acknowledgements

The authors would like to thank the Malaysian Government and Universiti Sains Malaysia (USM) for the Research Grant (No. 1001/PJJAUH/811115). HKF and JHG thank USM for the Research University Golden Goose grant (No. 1001/PFIZIK/811012). IAK is grateful to USM for a Postdoctoral Fellowship and Gokhale Centenary College, Ankola, India, for study leave. JHG also thanks USM for the award of a USM fellowship.

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