Heavy Neutral and Anionic Pnictogen Thiocyanates

Article abstract of DOI:10.1021/acs.inorgchem.9b00378

When [PPN]SCN (1; PPN = [Ph₃P-N-PPh₃]) is treated with Me₃Si-SCN in methanol, [PPN][H(NCS)₂] (2), a hydrogen diisothiocyanate salt bearing the [H(NCS)₂]^- anion, was generated, isolated, and fully characterized. Pure heavy E(NCS)₃ [E = Sb (3), Bi (4)] species were obtained from the reaction of EF₃ and an excess of Me₃Si-SCN, while the tetrahydrofuran (THF) solvates E(NCS)₃·THF were isolated when the product was recrystallized from THF. When 2 equiv of 1 was combined with Me₃Si-SCN and SbF₃, [PPN]₂[Sb(NCS)₅] (5) could be isolated. When 1 was added to BiF₃, [PPN]₂[Bi(NCS)₃(SCN)₂·THF] (6·THF), containing three SCN^- ions coordinating via the N atom and two coordinating via the S atom, was isolated after recrystallization from THF. The structures of 1, 2, 3·THF, 4·THF, 5, and 6·THF were determined. 3·THF displayed a typical [3 + 3] coordination mode with a trigonal-pyramidal environment in the first coordination sphere of the Sb³⁺ ion, and the dianion of 5, [Sb(NCS)₅]^2-, featured a classical square-pyramidal molecular geometry around the Sb³⁺ ion with one additional Menshutkin-type interaction to one aryl ring of the [PPN]⁺ cation. 4·THF exhibited a distorted pentagonal-bipyramidal structure within a two-dimensional network, while in 6·THF, an octahedrally surrounded Bi³⁺ ion was observed.

Full text of DOI:10.1021/acs.inorgchem.9b00378

Article
pubs.acs.org/IC
Cite This: Inorg. Chem. XXXX, XXX, XXX−XXX
Heavy Neutral and Anionic Pnictogen Thiocyanates
†
†
,†,‡
̈
̈
Soren Arlt, Jorg Harloff, Axel Schulz,*
Alrik Stoffers,† and Alexander Villinger†
†Institut fu
̈
r Chemie and Leibniz-Institut fu
̈
r Katalyse, Universitat Rostock, Albert-Einstein-Straße 3a, 18059 Rostock, Germany
‡
̈
S
* Supporting Information
ABSTRACT: When [PPN]SCN (1; PPN = [Ph3P−N−PPh3]) is treated with Me3Si−SCN
in methanol, [PPN][H(NCS)2] (2), a hydrogen diisothiocyanate salt bearing the
[H(NCS)2]− anion, was generated, isolated, and fully characterized. Pure heavy E(NCS)3
[E = Sb (3), Bi (4)] species were obtained from the reaction of EF3 and an excess of Me3Si−
SCN, while the tetrahydrofuran (THF) solvates E(NCS)3·THF were isolated when the
product was recrystallized from THF. When 2 equiv of 1 was combined with Me3Si−SCN
and SbF3, [PPN]2[Sb(NCS)5] (5) could be isolated. When 1 was added to BiF3,
[PPN]2[Bi(NCS)3(SCN)2·THF] (6·THF), containing three SCN− ions coordinating via the
N atom and two coordinating via the S atom, was isolated after recrystallization from THF.
The structures of 1, 2, 3·THF, 4·THF, 5, and 6·THF were determined. 3·THF displayed a
typical [3 + 3] coordination mode with a trigonal-pyramidal environment in the first coordination sphere of the Sb3+ ion, and
the dianion of 5, [Sb(NCS)5]2−, featured a classical square-pyramidal molecular geometry around the Sb3+ ion with one
additional Menshutkin-type interaction to one aryl ring of the [PPN]+ cation. 4·THF exhibited a distorted pentagonal-
bipyramidal structure within a two-dimensional network, while in 6·THF, an octahedrally surrounded Bi3+ ion was observed.
Scheme 1. Known Synthese of P(SCN)3
INTRODUCTION
■
̈
Thiocyanic acid, HSCN (first known as Schwefelblausaure,
which is German for sulfur blue acid), was already observed in
1790 by Winterl, 1798 by Buchholz,1 and 1804 by Rink and
prepared in 1808 by Porret.2 Its composition was determined
by Berzelius in 1820, and he also introduced the old name
rhodanic acid (from Greek for red) because iron(III)
thiocyanate is a deep-red complex. Thiocyanate salts can be
prepared from cyanides and sulfur in the melt.2 In addition to
HSCN, an isomer is also known, namely, isothiocyanic acid
(HNCS, also known as thiocarbimide). The thiocyanate ion,
like the azide, cyanide, or cyanate, is referred to as a linear
pseudohalide that easily forms salts with alkali metals such as
potassium thiocyanate (KSCN, also known as potassium
rhodanide).3−7
A structural characterization of the phosphorus trithiocya-
nate liquid at room temperature was not possible because of its
instability.13 There are only a few references with regard to the
heavier E(SCN)3 (E = As, Sb) molecules, which were obtained
analogous to P(SCN)3 in the reaction of the element
trichlorides with 3 equiv of AgSCN.14,15 The arsenic
trithiocyanate could be isolated at lower temperatures as a
white solid but decomposed readily at room temperature.14
Antimony trithiocyanate coordination compounds with further
neutral ligands such as naphthalene, pyridine, or urea were
isolated and characterized by elemental analysis.16,17 Structural
characterization is unknown for the pure arsenic and antimony
trithiocyanate compounds. The situation is different with
bismuth trithiocyanate, which was already discussed by Bender
as early as 1887.18 The first structural characterization of
bismuth trithiocyanate stabilized by 5-amino-1,2,4-dithiazole-
3-thione was achieved by Bensch et al. in 1989.19 In 2010, the
group of Ruck succeeded in synthesizing a water-bridged
complex of bismuth trithiocyanate.20 For this purpose, the
carbonate (BiO)2CO3 was reacted with freshly prepared
HSCN. To the best of our knowledge, a solvent-free structure
is not yet known. Also, relatively little is known about ionic
̈
As early as 1873, Lossner converted phosphorus trichloride
with KSCN into P(SCN)3 in an alcoholic solution.8 Shortly
thereafter, the reactions of PCl3, AsCl3, and SbCl3 with metal
thiocyanates (MSCN, where M = alkali metal) were studied by
different groups.9 Formation of the thiocyanates P(SCN)3,
As(SCN)3, and Sb(SCN)3 was assumed because, upon contact
of these E(SCN)3 (E = P, As, and Sb) species with water,
HSCN was observed. In 1902, Dixon studied the reaction of
PCl3 with KSCN in detail in order to investigate the behavior
of P(SCN)3 toward alcohol.10 It was Soderback who advanced
thiocyanate chemistry and dealt, in particular, with the
synthesis of free HSCN and its salts. In the course of these
investigations, he examined the effect of HSCN−ether
solutions on pure arsenic and antimony, whereby he could
isolate a yellow hygroscopic oily solid.11 To date, various
synthetic routes to P(SCN)3 have been published, most of
them starting from PCl3 and metal thiocyanates such as
AgSCN, Hg(SCN)2, or NH4SCN (Scheme 1).12,13
̈
̈
Received: February 8, 2019
© XXXX American Chemical Society
A
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pnictogen thiocyanate compounds such as [E(SCN)n]m− (EIII
= pnictogen, n = 4−6, m = 1−3; EV, n = 6, m = 1). In 1982,
Dillon and Platt described the synthesis of hexathiocyanato-
phosphate ([P(NCS)6]−) and observed the decomposition of
that compound at room temperature.21 Partially substituted
compounds of the type [PX6−n(SCN)n]− (X = F, Cl; n = 1−5)
were also isolated by Dillon and Platt, however, without
structure determination.21,22 Arsenic variants of anions of the
type [AsX6−n(SCN)n]− or [AsX4−n(NCS)n]− (X = halogen) are
not known; however, salts bearing [As(CH3SO3)(NCS)3]−
with a methyl sulfate instead of a halide were reported in
1987.23 The heavier homologues [E(CH3SO3)(NCS)3]− (E =
Sb, Bi) were described by Kapoor et al.23 The anion
[SbPh(NCS)3]− was structurally characterized in 1995 by
Sowerby et al.24 All hitherto known antimony thiocyanate
species25−28 are of the type [SbR(NCS)3]− or [Sb(OR)-
(NCS)3]− (R = organic substituent). To the best of our
knowledge, a pure antimony trithiocyanate could not yet be
structurally characterized, although Bertazzi and Alonzo
described the synthesis of [NH4][Sb(NCS)4] (Scheme 2) in
1989. On the basis of mass spectrometry data, they postulated
a possible structural arrangement of the thiocyanates around
the antimony.17
Figure 1. Ball-and-stick representation of the molecular structure of 2
in the crystal. Selected bond lengths (Å) and angles (deg): N1−H1
1.33(5), N2−H1 1.21(5), N1−C1 1.155(6), C1−S1 1.615(5), N2−
C2 1.155(6), C2−S2 1.606(5), N1···N2 2.533(7); N1−H1−N2
173(5), H1−N1−C1 151(2), H1−N2−C2 169(2), N1−C1−S1
178.5(4), N2−C2−S2 179.0(5), C1−N1−N2 165.5(2). Shown is
only one of the two independent molecules.
of [PPh4][H(NCS)2], which was obtained accidently as a
byproduct in the reaction of uranium tetrachloride with
sodium thiocyanate and tetraphenylphosphonium chloride.51
Moreover, a polymorph of 1 has been reported previously.52
With pure thiocyanate salts in hand, we attempted the
synthesis of pure, solvate-free E(SCN)3 (E = Sb, Bi). In the
reaction of antimony trifluoride with trimethylsilyl isothiocya-
nate in THF, the previously structurally unknown Sb(SCN)3·
THF (3·THF) and Bi(SCN)3·THF (4·THF) could be
synthesized (Scheme 4, eq 3). When both compounds (3·
THF and 4·THF) are subjected to prolonged pumping or
when the reaction was carried out in an excess of Me3Si−SCN
(without THF), the solvent-free E(SCN)3 can be obtained.
Despite storage under argon as a protective gas, a discoloration
to yellow and later orange in the crystallization process was
observed after a few days, which indicated slow decomposition
even at ambient conditions.
Scheme 2. Synthesis of [Me4N][Sb(NCS)4]
In 2009, Renz et al. mentioned the synthesis of iron/
antimony rhodanide clusters, however, without any structural
data.29,30 As early as 1976 and 1994, Galdecki et al. and
Crispini et al. reported on the structure of salts containing the
anions [Bi(NCS)4]− and [Bi(NCS)6]3−, respectively.31,32
Following our long-standing interest in pseudohalide chem-
istry,33−48 we report here in detail on the synthesis and
structure of antimony and bismuth thiocyanates.
Salts containing the [E(SCN)5]2− ion (E = Sb, Bi) were
prepared in the reaction of the trifluoride EF3 with 2 equiv of 1
and 3 equiv of Me3Si−SCN in MeCN. Crystals of [PPN]2[E-
(SCN)5] salts were obtained after recrystallization from THF.
Interestingly, [PPN]2[Sb(SCN)5] (5) crystallized as a pure
salt, whereas [PPN]2[Bi(SCN)5·THF] (6·THF) crystallized as
THF monosolvate.
Spectroscopic Characterization. The heavy pnictogen
trithiocyanates (3 and 4) must be stored under inert gas at a
lower temperature because they decompose slowly at room
temperature and are very sensitive to oxygen as well as
moisture (Table 1). Above 100 °C, a fairly rapid decom-
position occurs, beginning with coloration to a deep-orange
color. A similar thermal behavior was found for the
pentathiocyanate complexes. IR and Raman spectroscopic
studies revealed the existence of SC−N stretching modes in
the expected range between 1930 and 2122 cm−1. A strong
splitting of the SC−N stretching vibration was observed,
especially for the pentathiocyanate complexes because the
SCN ions can be differently linked to the pnictogen ions (see
below). IG 13C NMR spectroscopy studies (IG = inverse
gated) were performed to determine the number of SCN
groups coordinated to the formal Sb3+ ion of [PPN]2[Sb-
(NCS)5] (5) in solution. For compound 5, five magnetically
equivalent SCN ions could be determined by calibration and a
RESULTS AND DISCUSSION
■
Synthesis. We started this project with a detailed study of
the solubilities of thiocyanates in various solvents, e.g., water,
methanol (MeOH), acetonitrile (MeCN), dichloromethane
(CH2Cl2), or even ionic liquids such as 1-butyl-3-methyl-
imidazolium triflate (BMimOTf). We were particularly
interested in the synthesis of [WCC]SCN salts (WCC =
weakly coordinating cation) such as bis(triphenylphosphine)-
iminium thiocyanate {[PPN]SCN (1), where PPN+ = [Ph3P−
N−PPh3]+} to reduce the cation−anion interaction.44,49,50
As expected, KSCN dissolves well in protic polar solvents
but poorly in organic solvents, while 1 dissolves well in MeOH,
CH2Cl2, and MeCN but poorly in water. Surprisingly, in the
reaction of [PPN]Cl with an excess of KSCN, we obtained
[PPN][H(NCS)2] (2; Figure 1) rather than the expected 1,
which prompted us to find a direct synthesis. First, in a next
step, the desired 1 could be obtained from water by a modified
literature synthesis, exploiting the poor solubility of 1 in water
(Scheme 3, eq 1).35 Second, for compound 2, a direct
synthetic route could be established starting from 1 and
Me3Si−SCN in MeOH with isolated yields >98% (Scheme 3,
eq 2). These two routes enabled us to prepare, isolate, and
structurally characterize pure 1, 1·THF, and 2. It should be
mentioned that in 2016 Nuzzo et al. published structural data
B
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Scheme 3. Syntheses of 1 and 2
compared to ∑rcov= 2.11 Å)53 and three rather long Sb···S
(average 3.098 Å, compared to ∑rvan der Waals = 3.86 Å)54
distances are found. Actually, there are two further, rather long
Sb···S distances (average 3.818 Å) that are within the sum of
the van der Waals radii (Table 2), which means a [3 + 3 + 2]
coordination55 mode could also be discussed. A view along the
c axis in the unit cell features the 4-fold screw axis (Figure 3,
right).
Similar to the structure of 3, the THF solvate 3·THF also
exhibits three short Sb−N bond lengths (average 2.107 Å;
Table 2), leading to a formal trigonal-pyramidal arrangement
of the strongly bound three SCN− ions (Figure 4, left).
However, the THF molecule, bound via the O atom, features a
bond length of 2.421(5) Å (cf. ∑rcov = 2.03 Å;53 ∑rvan der Waals
= 3.59 Å),54 which lies between a covalent and van der Waals
type Sb−O bond. Hence, a bisphenoidal (pseudotrigonal-
bipyramidal) environment around the Sb atom can also be
assumed in accordance with the rather large O1−Sb1−N1
angle of 156.5(1)°. In addition, two van der Waals interactions
can be discussed between the Sb3+ and two SCN ions of two
adjacent Sb(SCN)3 moieties [avarage d(Sb···S) = 3.209 Å]. So,
either a [3 + 1 + 2] or a [4 + 2] coordination mode can be
discussed.55 Again there are also two very weak Sb···S van der
Waals interactions [d(Sb···S) = 3.885 Å], as found in 3 (vide
supra). The view along the b axis in the unit cell displays 1,1
coordination via the S atom of two different SCN− ions,
leading to 4-membered Sb2S2 rings, as well as 1,3 coordination
of two different SCN− ions, resulting in 8-membered
Sb2(SCN)2 rings (Figure 4, right).
5 crystallizes in the monoclinic space group P21/c with four
formula units in the unit cell. The anion adopts a distorted
square-pyramidal geometry with a SbN5 core (Figure 5, left).
The Sb−N bond lengths in the square base are between
2.206(3) and 2.322(4) Å. In contrast, the bond to the apical
thiocyanate group is significantly shorter with 2.045(3) Å,
which is even slightly below the sum of the covalent radii
[∑rcov(Sb−N) = 2.11 Å].53 The angles between the basal and
apical thiocyanates are all less than 90°. The thiocyanate
ligands coordinate all via the N atom of the thiocyanate to the
Sb3+ ion and show an angled arrangement [∠(Sb−N−C)
between 140.1(3) and 169.1(3)°]. Compared to the Sb−N
bond lengths in 3, the averaged Sb−N distances in the first
coordination sphere are slightly elongated (2.222 vs 2.098 Å)
due to the increased coordination number.
Scheme 4. Synthesis of E(SCN)3 and [PPN]2[E(SCN)5] (E
= Sb, Bi)
comparison with the signal of the cation [PPN]+ (Figure 2).
The rather broad 13C NMR shift at 138 ppm was assigned to
the C atom of the five thiocyanate groups, which is the most
downfield-shifted signal in the spectrum of 5. It was impossible
to resolve the intramolecular dynamic exchange within the
[Sb(SCN)5]2− ion.
Structure Elucidation. Besides the structures of the
starting materials 1 (Figure S1 and Table S4), 1·THF (Figure
S2), and 2 (Figure 1), the structures of Sb(NCS)3 (3; Figure
3), 3·THF (Figure 4), 5 (Figures 5 and 6), 4·THF (Figure 7),
and 6·THF (Figure 8) were determined. Selected average
bond lengths are summarized in Table 2. While Figures 1 and
3−8 show ball-and-stick represantations of the pnictogen
thiocyanate compounds for clarity, ORTEP representations
can be found in Figures S1−S8. Crystallographic details are
summarized in Tables S1−S3.
̅
2 crystallizes in the triclinic space group P1 with two
independent molecules and four formula units per unit cell.
Because most of the structural data of the anion in 2 are similar
to those of the accidently found [PPh4][H(NCS)2] salt
(monoclinic space group P21/c), we will abstain from a
extensive discussion and refer to the work of Nuzzo et al.51
However, a closer look at the C−N−N angles revealed
significantly different values [Figure 1; cf. ∠(C1−N1−N2) =
165.5(2) vs 171.6(2)°], which can be attributed to a rather flat
potential energy surface regarding the C−N−N angle. Hence,
a change from the [PPh4]+ ion (Nuzzo et al.) to the [PPN]+
cation, as in this work, has a considerable influence on the
structural parameters that are associated with a flat potential
energy surface (such as the C−N−N angle or even localization
of the proton).
3 crystallizes in the tetragonal space group I41cd with 16
formula units in the unit cell. In contrast, 3·THF crystallizes in
the monoclinic space group P21/n with four formula units. The
neutral, solvent-free compound 3 exhibits a distorted trigonal-
pyramidal molecular structure (Figure 3, left), in which the
coordination sphere of the central antimony is extended by
coordination via the sulfur to three adjacent thiocyanate
groups, finally leading to [3 + 3] coordination.55 In accordance
with this consideration, three short Sb−N (average 2.098 Å,
At a first glance, there are no significant interionic cation−
anion or anion−anion contacts (shortest distance S2···S4′
4.248(2) Å; Figure 5, right). However, a closer look at the Sb···
Table 1. Spectroscopic Details (Melting Points in °C and CN Stretching Modes in cm−1) of Thiocyanate Species 1−6
1
2
3·THF
4·THF
5
6·THF
a
a
MP
νCN,IR
193
129
130
1932 (vs,br)
121
2083 (s,br)
141
114
2052 (m) 2048
2073 (m), 2037 (m), 2013 (s),
1988 (s), 1975 (s)
2114 (w), 2102 (m), 2033 (s),
1975 (m), 1944 (s)
(s,br)
νCN,Raman 2052(5)
2051(1)
2122(2), 2083(4), 2060(3),
2029(2), 2004(2)
2105(10),
2072(2)
2076(1), 2068(1), 2042(2),
2026(5), 1993(1)
2116(5), 2054(1), 1980(1),
1950(1),
a
Decomposition.
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Figure 2. IG 13C NMR spectrum of 5 in CD3CN. The inset shows the enlarged resonances in the region 127−139 ppm that correspond to the
structural formula on the right.
Caryl,PNP distances revealed a weak cation−anion interaction, as
manifested by a shortened Sb···Caryl,PNP distance [d(Sb1···C58)
= 3.677(4) Å, compared to ∑rvan der Waals = 3.76 Å],54 which
can be understood as a weak Menshutkin-type interaction
(Figure 6).56−58
Yellow crystals of 4·THF crystallize in the monoclinic space
group P21/c. As illustrated in Figure 7 (top), the coordination
around the Bi3+ ion is best described by a strongly distorted
pentagonal bipyramid. Contrary to the analogous antimony
structure 3·THF (Figure 4), there is no clear molecular
Bi(SCN)3 entity with a [3 + 3] coordination mode.55 All Bi−N
[2.412−2.617 Å, compared to ∑rcov(Bi−N) = 2.22 Å and
∑rvdW(Bi···N) = 3.62 Å] and Bi−S [2.751−2.847 Å, compared
Table 2. Selected Average Bond Lengths (Å) of 2−6 along
with the Sum of the Covalent and van der Waals Radii
2
3
3·THF
4·THF
5
6·THF
a
b
E−N
E−S
E−O
2.534
3.557
2.098
3.098
2.107
3.209
2.421
2.505
2.802
2.555
Bi−N
2.222
8.107
2.364
2.788
2.648
Bi−O
c
Sb−N
Sb−S
Sb−O
Bi−S
53
∑rcov
∑rvdW
2.11
3.61
2.43
3.86
2.03
3.58
2.22
3.62
2.54
3.87
2.14
3.59
54
a
b
E = N, N1, ..., N2 distance. E = C, shortest S···Caryl,cation distance.
Shortest Sb···S distance between adjacent anions.
c
Figure 3. Left: Ball-and-stick representation of the molecular structure of 3 in the crystal. Selected bond lengths (Å) and angles (deg): Sb1−N1
2.103(3), Sb1−N2 2.099(2), Sb1−N3 2.093(2), Sb1···S3′ 3.1178(6), Sb1···S3′′ 3.0479(8), Sb1···S3‴ 3.1293(7), N1−C1 1.182(4), N2−C2
1.165(4), N3−C3 1.175(4), C1−S1 1.600(3), C2−S2 1.613(3), C3−S3 1.607(3); N1−Sb1−N2 87.9(1), N1−Sb1−N3 85.6(1), N2−Sb1−N3
83.87(9), Sb1−N1−C1 138.9(3), Sb1−N2−C2 175.6(2), Sb1−N3−C3 141.6(2), N1−C1−S1 177.7(3), N2−C2−S2 179.0(3), N3−C3−S3
178.1(3). Symmetry code: ′, 1 − x, y, −0.5 + z, ′′, 1 − y, 0.5 + x, 0.25 + z; ‴, 1 − x, y, 0.5 + z. Right: Unit cell, viewed along the c axis.
D
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Figure 4. Left: Ball-and-stick representation of the molecular structure of 3·THF in the crystal. Selected bond lengths (Å) and angles (deg): Sb1−
N1 2.151(2), Sb1−N2 2.070(2), Sb1−N3 2.101(3), N1−C1 1.162(4), N2−C2 1.182(3), N3−C3 1.178(4), C1−S1 1.610(3), C2−S2 1.586(3),
C3−S3 1.600(3), Sb1···S1′ 3.140(2), Sb1···S3′ 3.2774(8), Sb1---O1 2.421(5); N1−Sb1−N2 86.36(9), N1−Sb1−N3 85.9(1), N2−Sb1−N3
86.5(1), Sb1−N1−C1 145.3(3), Sb1−N2−C2 138.2(2), Sb1−N3−C3 146.2(2), N1−C1−S1 178.3(3), N2−C2−S2 176.7(2), N3−C3−S3
176.7(3), O1−Sb1−N1 156.4(2), O1−Sb1−N2 76.6(2), O1−Sb1−N3 77.0(2). Right: Unit cell, viewed along the b axis.
Figure 5. Left: Ball-and-stick representation of the molecular structure of 5 in the crystal. Selected bond lengths (Å) and angles (deg): Sb1−N1
2.322(4), Sb1−N2 2.254(4), Sb1−N3 2.045(3), Sb1−N4 2.206(3), Sb1−N5 2.284(3), N1−C1 1.154(5), C1−S1 1.620(4), N2−C2 1.158(5),
C2−S2 1.609(4), N3−C3 1.171(4), C3−S3 1.591(4), N4−C4 1.163(5), C4−S4 1.606(4), N5−C5 1.173(5), C5−S5 1.617(4); N1−Sb1−N2
90.7(2), N1−Sb1−N3 79.5(2), N1−Sb1−N4 162.4(2), N1−Sb1−N5 90.3(2), N2−Sb1−N3 81.3(2), N2−Sb1−N4 88.4(2), N2−Sb1−N5
163.2(2), N3−Sb1−N4 83.0(2), N3−Sb1−N5 82.3(2), N4−Sb1−N5 85.5(2), C1−N1−Sb1 149.9(3), C2−N2−Sb1 169.1(3), C3−N3−Sb1
161.2(3), C4−N4−Sb1 140.1(3), C5−N5−Sb1 149.8(3), N1−C1−S1 178.9(4), N2−C2−S2 177.5(4), N3−C3−S3 178.5(4), N4−C4−S4
177.4(4), N5−C5−S5 178.2(3). Right: Unit cell, viewed along the c axis.
sum of the covalent radii but significantly shorter than the sum
of the van der Waals radii (Table 2).53,54 The same holds true
for the Bi−O bond lengths with the THF molecule [2.555 Å,
compared to ∑rcov(Bi−O) = 2.14 Å and ∑rvdW(Bi···O) = 3.59
Å].53,54 Taking these bond lengths and bond angles into
account, the pentagon is composed of N1, N2, N3, S3‴, and
O1, while the two apical positions are occupied by S1′ and
S2′′, in accordance with the rather large S1′−Bi1−S2′′ angle of
164.43(4)°. As depicted in Figure 7, the most prominent
structural feature within the cell is the existence of three
(almost trigonally arranged) 8-membered rings composed of
Bi(SCN)2 inversion dimers (always with a 1,3 coordination of
the SCN− ion), leading to the formation of a two-dimensional
network. The coordination around the Bi3+ cations in 4·THF
Figure 6. Ball-and-stick representation of the Menshutkin-type
interaction in 5 in the crystal: Sb1···C58 3.677(4) Å.
resembles that described by Ruck et al. for Bi(SCN)3·1/2H2O
(triclinic space group P1
̅
),20 for which a coordination mode of
[7 + 1] for one Bi3+ (four S, three N, and one O donor
atoms)55 and a heptacoordination for a second independent
Bi3+ ion (three N, three S, and one O donor atoms) are
to ∑rcov(Bi−S) = 2.54 Å, compared to ∑rvdW(Bi···S) = 3.87
Å] bond lengths are only slightly elongated compared to the
E
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discussed. However, in contrast to our structure, Bi-
(SCN)3·1/2H2O exhibits 1,1 SCN− coordination along with a
μ2-bridging water molecule, resulting in the formation of Bi2OS
4-membered rings.20
Yellow crystals of 6·THF crystallize in the monoclinic space
group P21 with two formula units per cell. Interestingly, there
are no significant interactions between the cations and anions
or between the complex anions [shortest interanionic distances
d(Bi···S) = 6.381(2), compared to ∑rvdW(Bi···S) = 3.87 Å;
Figure 8].54 Even more puzzling in comparison with the
analogous antimony compound is the fact that three of the five
thiocyanate ions coordinate to the Bi3+ ion via the N atom,
while two SCN− ions are linked via the S atom. In addition, the
THF molecule also coordinates via the O atom to the Bi3+
ion. All in all, this results in a slightly distorted octahedral co-
ordination environment for the Bi3+ center. Because there is no
significant interaction between the anions [shortest distance
d(Bi···Bi) = 9.8913(5) Å], it follows that each octahedral, Bi3+-
containing anion, [Bi(NCS)3(SCN)2(THF)]2−, is exclusively
surrounded by [PPN]+ cations. Interestingly, the distortion of
the octahedral BiS2N3O core is fairly small, as manifested by
the S4−Bi1−S5 (178.1°), N−Bi−N (between 84.3 and 85.2°),
and N−Bi−S (88.3−92.1°) angles. In comparison with the
bond lengths in 4·THF, the averaged Bi−N and Bi−S bond
lengths in 6·THF are significantly shorter [d(Bi−N) = 2.364 vs
2.505 Å and d(Bi−S) = 2.787 vs 2.802 Å; Table 2]. Only the
Bi−O bond length is slightly longer with 2.648(5) Å,
compared to 2.555(7) Å (4·THF). Interestingly, in the already
reported octahedral [Bi(SCN)6]3− ion, a slightly distorted BiS6
octahedron is found, but no coordination via the N atom of the
SCN− ion is found in 6·THF.32 SCN/NCS isomerism has
been found before, for example, for many transition-metal
SCN complexes.59
Figure 7. Top: Ball-and-stick representation of the coordination
environment around the Bi1 center in 4·THF in the crystal. Selected
bond lengths (Å) and angles (deg): Bi1−N1 2.485(5), Bi1−N2
2.412(5), Bi1−N3 2.617(5), N1−C1 1.151(7), N2−C2 1.158(7),
N3−C3 1.153(7), C1−S1 1.658(6), C2−S2 1.643(5), C3−S3
1.153(7), Bi1−S1′ 2.808(2), Bi1−S2′′ 2.847(2), Bi1−S3‴ 2.751(2),
Bi1−O1 2.555(7); N1−Bi1−N2 147.4(2), N1−Bi1−N3 73.2(2),
N2−Bi1−N3 139.3(2), Bi1−N1−C1 161.8(4), Bi1−N2−C2
159.0(4), Bi1−N3−C3 161.3(4), N1−C1−S1 178.0(5), N2−C2−
S2 177.8(5), N3−C3−S3 179.0(5), O1−Bi1−N1 127.7(3), O1−
Bi1−N2 73.9(5), O1−Bi1−N3 74.4(6). Bottom: view along the a axis
of a 2 × 2 × 2 cell representation. Symmetry codes: ′, 1 − x, −0.5 + y,
1.5 − z; ′′, 1 − x, 1 − y, 1 − z; ‴, 1 − x, 0.5 + y, 1.5 − z. THF
molecules are disordered.
CONCLUSION
■
In summary, an easy route to synthesizing solvate-free heavy
pnictogen trithiocyanates E(NCS)3 (E = Sb, Bi) is the reaction
of EF3 with an excess of Me3Si−SCN, wherein the Me3Si−
Figure 8. Left: Ball-and-stick representation of the coordination environment around the Bi1 center in 6·THF in the crystal. Selected bond lengths
(Å) and angles (deg): Bi1−N1 2.499(6), Bi1−N2 2.282(6), Bi1−N3 2.361(6), Bi1−S4 2.739(2), Bi1−S5 2.836(2), N1−C1 1.157(9), N2−C2
1.036(9), N3−C3 1.160(9), N4−C4 1.16(2), N5−C5 1.17(1), C1−S1 1.617(8), C2−S2 1.647(9), C3−S3 1.618(7), C4−S4 1.64(2), C5−S5
1.648(8), Bi1---O1 2.648(5); N1−Bi1−N2 84.3(2), N1−B1−N3 169.3(2), N1−Bi1−S4 89.2(2), N1−Bi1−S5 92.1(2), N1−Bi1−O1 111.6(2),
N2−Bi1−N3 85.1(2), N2−Bi1−S4 90.4(2), N2−Bi1−S5 88.3(2), N2−Bi1−O1 160.5(2), N3−Bi1−S4 89.3(2), N3−Bi1−S5 89.2(2), N3−Bi1−
O1 78.5(2), S4−Bi1−S5 178.1(1), S4−Bi1−O1 79.1(2), S5−Bi1−O1 101.8(2), Bi1−N1−C1 173.8(5), Bi1−N2−C2 123.9(5), Bi1−N3−C3
159.5(5), Bi1−S4−C4 102.4(3), Bi1−S5−C5 94.0(2), N1−C1−S1 179.7(8), N2−C2−S2 174.2(7), N3−C3−S3 177.8(6), N4−C4−S4 176.1(8),
N5−C5−S5 179.3(7). Right: unit cell, viewed along the a axis.
F
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(m), 997 (s), 972 (m), 908 (s), 847 (m), 797 (w), 744 (m), 723 (s),
687 (vs), 663 (s), 619 (s), 608 (s), 571 (s), 542 (vs). Raman (633
nm, D00, ×10, 20s, 20 acc., cm−1): 3056 (4), 2051 (1), 1588 (4),
1573 (1), 1182 (1), 1160 (1), 1109 (3), 1025 (4), 1000 (10), 662
(3), 613 (2), 357 (1), 282 (0), 264 (2), 256 (1), 246 (1), 232 (2),
227 (2).
SCN acts as both a reactant and a solvent. E(NCS)3 solvates
can be obtained upon recrystallizaion from THF or other
solvents with donor properties. The treatment of EF3 with an
excess of Me3Si−SCN in the presence of 1 always results in the
formation of formal [PPN]2[E(SCN)5] salts. However, while
the [Sb(NCS)5]2− ion features a square-pyramidal molecular
geometry around the Sb3+ ion with five Sb−NCS bonds, the
analogous bismuth species was isolated as solvate [Bi-
(NCS)3(SCN)2(THF)]2−, in which the Bi3+ ion sits in an
octahedral molecular environment with three N-linked and
two S-bound thiocyanate ions, in addition to one O atom from
the THF donor solvent. All discussed antimony(III) and
bismuth(III) thiocyanate complexes feature a stereochemically
active lone pair, which has been discussed in the literature for
antimony(III) and bismuth(III) azides as well as cyanides.36,45
Furthermore, we have presented a straightforward synthesis for
hydrogen diisothiocyanate salts such as 2. This high-yielding
facile synthesis begins with the synthesis of pure 1, followed by
the addition of Me3Si−SCN in MeOH, which leads to the in
situ formation of HSCN and Me3Si−O−Me.
Sb(NCS)3/Sb(NCS)3·THF (3/3·THF). SbF3 (0.5 g, 2.8 mmol) was
dissolved in THF (10 mL). Subsequently, trimethylsilyl isothiocya-
nate (3.5 mL, 3.305 g, 25.2 mmol) was added and stirred for 16 h at
ambient temperature. After removal of the solvent in vacuo, the
product 3·THF was isolated with a yield of 0.870 g (84.4%). 3·THF
(366.9 g/mol). Mp: 130 °C (dec). Elem anal. Calcd (found): C,
22.41 (22.84); H, 2.15 (2.19); N, 11.34 (11.42); S, 26.66 (26.13). IR
(ATR, 25 °C, 128 scans, cm−1): 2980 (m), 2955 (m), 2930 (m), 2883
(m), 2490 (m), 2328 (w), 1932 (vs, br), 1603 (s), 1493 (s), 1479 (s),
1454 (s), 1446 (s), 1379 (s), 1362 (s), 1294 (s), 1254 (s), 1173 (s),
1136 (s), 1032 (s), 1013 (s), 953 (s), 916 (s), 885 (s), 827 (s), 766
(s), 663 (s), 582 (s), 528 (s). Raman (633 nm, D00, ×10, 30s, 30
acc., cm−1): 2982 (0), 2937 (0), 2892 (0), 2122 (2), 2083 (4), 2060
(3), 2029 (2), 2004 (2), 1974 (3), 1608 (1), 1494 (1), 1381 (3),
1337 (1), 1310 (1), 1017 (1), 940 (1), 922 (0), 889 (0), 851 (0), 823
(0), 736 (1), 662 (3), 597 (1), 544 (4), 506 (10), 491 (2), 470 (3),
447 (0), 410 (3), 376 (1), 337 (8), 317 (2), 274 (0), 254 (3), 214
(5). MS (EI): m/z (%) 44 (15.3) ([CS]+), 76 (100), 77 (3.7), 78
(12.4) ([CS2]+), 121 (11.3), 123 (8.7) ([Sb]+), 179 (48.6), 180 (1.2),
181 (34.3) ([Sb(NCS)]+), 237 (50.0), 238 (2.0) 239 (41.0)
([Sb(NCS)2]+), 295 (44.9), 296 (2.6), 297 (42.3), 299 (4.1)
([Sb(NCS)3]+). Unsolvated 3 was obtained after prolonged pumping
or from the reaction of SbF3 in an excess of trimethylsilyl
isothiocyanate. Elem anal. Calcd (found): C, 12.17 (12.26); N,
14.20 (13.10).
Bi(NCS)3/Bi(NCS)3·THF (4/4·THF). BiF3 (0.5 g, 1.9 mmol) was
suspended in THF (10 mL). Subsequently, trimethylsilyl isothiocya-
nate (2.4 mL, 2.2 g, 16.9 mmol) was added and stirred for 16 h at
ambient temperature. The solution was filtered and the solvent
removed in vacuo. The product had a yield of 0.220 g (25%). Mp:
121 °C (dec). Elem anal. Calcd (found) for 4·THF: C, 18.46 (17.27);
H, 1.77 (1.38); N, 9.23 (9.71); S, 21.23 (22.57). 1H NMR (250 MHz,
THF-d8): δ 3.70−3.47 (m, OCH2), 1.85−1.62 (m, CH2), 0.30−0.23
(m), 0.20−0.10 (m), 0.05 to −0.02 (m). 13C NMR (62 MHz, THF-
d8): δ 68.4 (s), 26.6 (s), 2.2 (s), 0.1 (t, J = 7.6 Hz). IR (ATR, 25 °C,
32 scans, cm−1): 2945 (w), 2883 (w), 2083 (s, br), 1454 (s), 1365
(s), 1340 (s), 1022 (vs), 916 (s), 858 (vs), 771 (s), 731 (s), 662 (s).
Raman (633 nm, D06, ×10, 10s, 20 acc., cm−1): 2986 (0), 2886 (0),
2105 (10), 2072 (2), 915 (0), 885 (0), 773 (0), 750 (1), 731 (1), 463
(1), 447 (1), 443 (1), 223 (6), 194 (3), 157 (3). Pure 4 was obtained
after prolonged pumping in vacuo: C, 9.40 (9.37); H, 0.0 (0.17); N,
10.96 (10.70); S, 25.10 (24.60).
EXPERIMENTAL DETAILS
■
General Information. All manipulations were carried out with
oxygen- and moisture-free conditions under argon using standard
Schlenk or drybox techniques.
MeCN was dried over CaH2 and freshly distilled prior to use.
Tetrahydrofuran (THF) was dried over sodium/benzophenone and
freshly distilled prior to use. n-Pentane was dried over sodium/
benzophenone/tetraglyme [tetraglyme = Me(OCH2CH2)3OMe] and
freshly distilled prior to use. Trimethylsilyl isothiocyanate (ABCR)
was freshly distilled and degassed prior to use. SbF3 (Fluka) and BiF3
(ABCR) were used as received.
[PPN]SCN (1). [PPN]Cl (12.8 g, 22.3 mmol) was dissolved in hot
water (80 °C, 100 mL). KSCN (4.3 g, 44.2 mmol) was dissolved in
water (20 mL) too. Subsequently, both solutions were united. The
white residue was filtered and washed with water (3 × 20 mL). After
drying in air, the product was crystallized from acetone (75 mL). The
product 1 was dried in vacuo and isolated with a yield of 11.36 g
(85.3%). Mp: 193 °C. Elem anal. calcd (found): C, 74.48 (74.16); H,
1
5.07 (5.19); N, 4.69 (4.65); S, 5.37 (5.18). H NMR (300 MHz,
CD3CN): δ 7.72−7.41 (m). 13C NMR (75 MHz, CD3CN): δ 134.6
(s, Cpara), 133.5−133.1 (m, Cmeta), 130.6−130.2 (m, Cortho), 128.2
1
3
(dd, J[13C,31P] = 108 Hz, J[13C,31P] = 2 Hz, Cipso). 31P NMR (121
MHz, CD3CN): δ 20.8. IR (ATR, 25 °C, 32 scans, cm−1): 3059 (w),
3012 (w), 2052 (m), 1587 (w), 1576 (w), 1481 (w), 1435 (m), 1410
(w), 1319 (m), 1304 (s), 1286 (m), 1273 (s), 1178 (m), 1161 (w),
1111 (s), 1076 (m), 1026 (w), 997 (m), 974 (w), 924 (w), 795 (w),
764 (m), 741 (m), 719 (s), 702 (s), 687 (s), 663 (m), 615 (w), 546
(s), 528 (vs). Raman (633 nm, D00, ×10, 20s, 20 acc., cm−1): 3172
(0), 3148 (0), 3146 (0), 3143 (0), 3089 (0), 3063 (3), 3057 (3),
3013 (0), 2989 (0), 2052 (5), 1587 (5), 1574 (1), 1193 (0), 1185
(0), 1177 (1), 1162 (0), 1159 (0), 1152 (1), 1115 (2), 1107 (3),
1025 (5), 998 (10), 728 (1), 660 (3), 613 (2), 542 (0), 485 (0), 361
(0), 278 (0), 264 (1), 249 (1), 232 (3), 222 (1).
[PPN]2[Sb(NCS)5] (5). 1 (4.4 g, 7.37 mmol) and SbF3 (0.4394 g,
2.46 mmol) were dissolved in MeCN (20 mL). Subsequently,
trimethylsilyl isothiocyanate (4.0 mL, 3.724 g, 22.4 mmol) was added
and stirred at room temperature for 16 h. After removal of the solvent,
the crude product was recrystallized from a THF solution (25 mL).
The product was isolated with a yield of 1.254 g (11.4%). Mp: 141
°C. Elem anal. Calcd (found): C, 62.10 (61.53); H, 4.06 (4.00); N,
6.58 (6.28); S, 10.77 (10.56). 1H NMR (300 MHz, CD3CN): δ
7.72−7.42 (m, 60H, HPh), 3.99 (s, br), 3.69−3.60 (m, OCH2), 1.83−
1.77 (m, CH2). 13C NMR (75 MHz, CD3CN): δ 140.1 (SCN), 134.6
(Cpara), 133.4−133.1 (m, Cmeta), 130.6−130.1 (m, Cortho), 128.2 (dd,
[PPN][H(NCS)2] (2). 1 (1.475 g, 2.47 mmol) and trimethylsilyl
isothiocyanate (0.70 mL, 0.648 g, 4.94 mmol) were dissolved in
MeCN (2 mL). Subsequently, MeOH (0.1 mL, 0.079 g, 2.47 mmol)
was added and stirred for 12 h. The solvent and excess reactants were
removed in vacuo. The product had a yield of 0.956 g (98.8%). Mp:
129 °C. Elem anal. Calcd (found): C, 69.60 (69.65); H, 4.76 (4.96);
3
1J[13C,31P] = 108 Hz, J[13C,31P] = 2 Hz, Cipso). IG 13C NMR (63
MHz, CD3CN): δ 138.1 (s br, 5C, SCN), 134.6 (s, 12C, Cpara),
133.5−132.9 (m, 24C, Cme3ta), 130.6−130.1 (m, 24C, Cortho), 128.2
1
(dd, J[13C,31P] = 108 Hz, J[13C,31P] = 2 Hz, 12C, Cipso). 31P NMR
1
(121 MHz, CD3CN): δ 20.8. IR (ATR, 25 °C, 32 scans, cm−1): 3051
(w), 2073 (m), 2037 (m), 2013 (s), 1988 (s), 1975 (s), 1821 (w),
1587 (m), 1576 (w), 1481 (m), 1437 (s), 1298 (s), 1281 (s), 1265
(s), 1244 (s), 1182 (s), 1161 (m), 1109 (s), 1070 (m), 1026 (m), 997
(s), 984 (m), 953 (m), 928 (m), 922 (m), 887 (m), 856 (m), 847
(m), 825 (m), 804 (m), 762 (m), 744 (s), 721 (s), 689 (vs), 665 (s),
617 (m), 546 (vs), 530 (s). Raman (633 nm, D03, ×10, 10s, 20 acc.,
N, 6.49 (6.52); S, 9.78 (9.80). H NMR (300 MHz, CD3CN): δ
7.77−7.33 (m). 13C NMR (75 MHz, CD3CN): δ 134.6 (s, Cpara),
133.5−133.0 (m, Cmeta), 130.6−130.1 (m, Cortho), 128.2 (dd,
1J[13C,31P] = 108 Hz, 3J[13C,31P] = 2 Hz, Cipso). 31P NMR (121
MHz, CD3CN): δ 20.8. IR (ATR, 25 °C, 32 scans, cm−1): 3076 (w),
3055 (w), 2048 (s, br), 1589 (w), 1481 (w), 1435 (m), 1296 (s),
1279 (s), 1265 (s), 1184 (m), 1169 (m), 1113 (s), 1070 (m), 1024
G
DOI: 10.1021/acs.inorgchem.9b00378
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cm−1): 3058 (5), 2076 (1), 2068 (1), 2042 (2), 2026 (5), 1993 (1),
1589 (5), 1576 (1), 1440 (1), 1185 (1), 1164 (2), 1111 (3), 1030
(5), 1003 (10), 808 (1), 725 (0), 666 (4), 616 (3), 486 (3), 477 (1),
335 (1), 268 (2), 243 (3), 237 (3), 229 (1).
(2) Kohler, H. Die Fabrikation von Cyanverbindungen Aus
̈
̈
Tierischen Abfallen Und Produkten Der Trockenen Destillation.
Die Industrie der Cyanverbindungen; Vieweg + Teubner Verlag:
Wiesbaden, Germany, 1914; pp 60−101.
[PPN]2[Bi(NCS)3(SCN)2·THF] (6·THF). 1 (1.683 g, 2.82 mmol) and
BiF3 (0.25 g, 0.94 mmol) were stirred in MeCN (10 mL).
Subsequently, trimethylsilyl isothiocyanate (1.5 mL, 1.4 g, 8.46
mmol) was added and stirred at room temperature for 16 h. After
removal of the solvent, the crude product was recrystallized from a
THF solution (10 mL). The product was isolated with a yield of
1.243 g (26.8%). Mp: 114 °C. Elem anal. Calcd (found): C, 59.01
(59.34); H, 4.16 (4.19); N, 5.95 (5.65); S, 9.72 (9.47). 1H NMR (300
MHz, CD3CN): δ 7.85−7.33 (m, 60H, HPh), 3.73−3.55 (m, 4H,
OCH2), 1.86−1.74 (m, 4H, CH2). 13C NMR (75 MHz, CD3CN): δ
134.6 (s, Cpara), 133.5−133.1 (m, Cmeta), 130.6−130.2 (m, Cortho),
(3) Kauffman, G. B.; Foust, G. E.; Tun, P. Pseudohalogens: A
General Chemistry Laboratory Experiment. J. Chem. Educ. 1968, 45
(2), 141−146.
(4) Brand, H.; Schulz, A.; Villinger, A. Modern Aspects of
Pseudohalogen Chemistry: News from CN- and PN-Chemistry. Z.
Anorg. Allg. Chem. 2007, 633 (1), 22−35.
̈
(5) Stopenko, V. V.; Golub, A. M.; Kohler, H. Chemistry of
Pseudohalides; Elsevier: Amsterdam, The Netherlands, 1986.
(6) Birckenbach, L.; Kellermann, K. Uber Pseudohalogene (I). Ber.
Dtsch. Chem. Ges. B 1925, 58 (4), 786−794.
̈
(7) Brand, H.; Liebman, J. F.; Schulz, A.; Mayer, P.; Villinger, A.
Nonlinear, Resonance-Stabilized Pseudohalides: From Alkali Meth-
anides to Ionic Liquids of Methanides. Eur. J. Inorg. Chem. 2006, 21,
4294−4308.
1
3
128.2 (dd, J[13C,31P] = 108 Hz, J[13C,31P] = 2 Hz, Cipso), 68.3 (s,
OCH2), 26.2 (s, CH2). 31P NMR (121 MHz, CD3CN): δ 20.8. IR
(ATR, 25 °C, 32 scans, cm−1): 3057 (w), 3045 (w), 2989 (w), 2114
(w), 2102 (m), 2033 (s), 1975 (m), 1944 (s), 1824 (w), 1747 (w),
1587 (w), 1481 (m), 1437 (s), 1292 (m), 1279 (m), 1248 (s), 1180
(m), 1111 (s), 1070 (m), 1036 (m), 1024 (m), 997 (s), 951 (w), 937
(m), 924 (m), 876 (m), 851 (m), 804 (m), 760 (m), 744 (s), 721 (s),
689 (vs), 667 (s), 617 (m), 552 (s). Raman (633 nm, D03, ×10, 10s,
20 acc., cm−1): 3173 (0), 3150 (0), 3059 (5), 2955 (0), 2116 (5),
2054 (1), 1980 (1), 1950 (1), 1588 (5), 1575 (1), 1441 (1), 1188
(1), 1181 (1), 1165 (1), 1158 (1), 1111 (4), 1027 (4), 1002 (10),
710 (1), 668 (4), 1617 (2), 551 (0), 545 (0), 534 (1), 508 (1), 474
(1), 372 (1), 324 (5), 298 (1), 286 (1), 268 (3), 249 (5), 236 (7),
210 (10), 111 (2).
̈
(8) Lossner, L.; Kretzschmar, A.; Peitzsch, B.; Salomon, F.
Einwirkung von Phosphorchlorur Und von Benzoylchlorid Auf
̈
Rhodankalium. J. Prakt. Chem. 1873, 7 (1), 474−480.
(9) Dixon, A. E. LIX. − A Form of Tautomerism Occurring amongst
the Thiocyanates of Electronegative Radicles. J. Chem. Soc., Trans.
1901, 79, 541−552.
(10) Dixon, A. E. XVII. - The Action of Phosphorus Trithiocyanate
on Alcohol. J. Chem. Soc., Trans. 1902, 81 (168), 168−171.
̈
̈
̈
(11) Soderback, E. Studien Uber Das Freie Rhodan. Liebigs Ann.
Chem. 1919, 419 (3), 217−322.
̈
(12) Gall, H.; Schuppen, J. Uber Die Valenz-Grenze Bei
̈
Phosphorcyaniden Und Phosphorrhodaniden. Ber. Dtsch. Chem. Ges.
B 1930, 63 (2), 482−487.
ASSOCIATED CONTENT
* Supporting Information
■
(13) Fluck, E.; Goldmann, F. L.; Rumpler, K.-D. Pseudohalogenide
̈
S
Nichtmetallischer Elemente. II. Phosphor(III)-Isothiocyanat Und
Phosphor(III)-Isocyanat Die Systeme PCl3/P(NCS)3, PBr3/P(NCS)3
und PCl3/P(NCO)3. Z. Anorg. Allg. Chem. 1965, 338, 52−57.
(14) Sowerby, D. B. The Preparation and Properties of Some
Inorganic Isothiocyanates. J. Inorg. Nucl. Chem. 1961, 22, 205−212.
(15) Alonzo, G.; Consiglio, M.; Maggio, F.; Agozzino, P.; Bertazzi,
N. Identification of Antimony(III) Thiocyanato Species in the Mass
Spectra of Antimony Trifluoride and Ammonium Thiocyanate
Mixtures. Inorg. Chim. Acta 1989, 165 (1), 7−8.
The Supporting Information is available free of charge on the
ACS Publications website at DOI: 10.1021/acs.inorg-
chem.9b00378.
Details of the syntheses along with all experimental data
including all spectra (PDF)
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AUTHOR INFORMATION
Corresponding Author
*E-mail: axel.schulz@uni-rostock.de.
■
ORCID
Axel Schulz: 0000-0001-9060-7065
Alexander Villinger: 0000-0002-0868-9987
Notes
The authors declare no competing financial interest.
−
Dalton Trans. 1982, 7, 1199−1204.
ACKNOWLEDGMENTS
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Derivatives of Some Chlorofluorophosphate(V) Ions. J. Chem. Soc.,
Dalton Trans. 1983, 6, 1159−1164.
■
The authors thank the Deutsche Forschungsgemeinschaft
(DFG SCHU 1170/9-2), especially the priority program SPP
1708, for financial support. We thank Dr. D. Michalik
(University of Rostock) for measurement of the NMR spectra.
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