Syntheses, crystal structures, and optical properties of indium arsenic(III) oxide halides: In2(As2O5)Cl 2 and In4(As2O5)(As 3O7)Br3

Article abstract of DOI:10.1002/ejic.201100091

Two new indium arsenic(III) oxide halides, In₂(As ₂O₅)Cl₂ (1) and In₄(As ₂O₅)(As₃O₇)Br₃ (2), have been prepared by solid-state reaction. Both of

Full text of DOI:10.1002/ejic.201100091

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DOI: 10.1002/ejic.201100091
Syntheses, Crystal Structures, and Optical Properties of Indium Arsenic(III)
Oxide Halides: In2(As2O5)Cl2 and In4(As2O5)(As3O7)Br3
Xiao-Ming Jiang,[a,b] Zhong-Ning Xu,[a] Zhong-Yan Zhao,[a] Sheng-Ping Guo,[a]
Guo-Cong Guo,*[a] and Jin-Shun Huang[a]
Dedicated to Professor John D. Corbett on the occasion of his 85th birthday
Keywords: Layered compounds / Indium / Arsenic / Halides / Optical properties
Two new indium arsenic(III) oxide halides, In2(As2O5)Cl2 (1)
and In4(As2O5)(As3O7)Br3 (2), have been prepared by solid-
state reaction. Both of the compounds feature layered struc-
tures, in which indium–oxide halide octahedral rings or in-
dium–oxo chains are bridged by indium–oxide halide octahe-
dral dimers or indium–oxo unicapped trigonal prisms, and
the interlinkage between the rings or chains is also consoli-
dated by (As2O5)4– anions for 1, or (As2O5)4– and (As3O7)5–
anions for 2. Compound 2 is the first compound in which
three different indium-ion coordination geometries coexist
with the In3+ cations coordinated by O2– and Br– to form
[InO6], [InO7], and [InOBr3] units. The diffuse reflectance
spectra and band-structure calculations show that they are
wide-band-gap semiconductors.
genide system.[4,5] Metal cations contribute to the good per-
formances of materials, whereas lone-pair cations and hal-
ogens are in favor of forming “nice” structures, though the
relationship between structure and performance is always
complicated. Transition- and rare-earth-metal ions, which
are magnetically susceptible, can form some novel low-di-
mensional quantum-spin systems like MaLbXc (M = Fe, Co,
Ni, Cu; L = SeO3, TeO3, TeO5; X = Cl, Br; a = 2, 5; b = 1,
4; c = 1, 2).[5] Alkali (or alkaline earth) metal ions of high
polarization and d0 transition ions can form good NLO
materials with large second-harmonic generation (SHG)
efficiencies; these include Na2Mo3Te3O16, Na2W2TeO9, Ba-
Mo2TeO9, and M2W3TeO12 (M = Rb, Cs).[6] Rare-earth-
metal ions, which have several different energy levels, can
also form luminescent materials like Ln5MTe7O23Cl3 (Ln =
Pr, Nd; M = Mo, W).[7] To the best of our knowledge, al-
though many oxide halogenide compounds that contain
lone-pair cations have been prepared (those containing Se4+
and Te4+ in particular have received a great deal of atten-
tion[3,8]), and most metal ions in such types of compounds
are transition- and rare-earth-metal ions, relatively few of
them are found to contain group-15 elements. In particular,
the only known oxide halogenide compounds that contain
As3+ are oxoarsenate(III) chloride compounds[9] of lead
Introduction
Metal oxide halide compounds that contain so-called
lone-pair cations with stereochemically active electron pairs
such as Te4+, Se4+, Sb3+, and As3+ have been shown to form
a group of compounds with a high probability for novel
materials with low-dimensional crystal structures and excel-
lent chemical and physical properties, such as second-order
nonlinear optical (NLO), magnetic, and luminescent prop-
erties, and so on.[1–7] The active electron pairs in lone-pair
cations always “push” the oxide ligands toward one side of
the cation, thus leading to a highly asymmetric coordina-
tion geometry, which is essential to the discovery of new
NLO materials.[2] Crystal structures are often opened up by
terminal halogen atoms as well as lone-pair cations, which
are likely to form bonds only with O in oxide halogenides
to make the metal cations take low-dimensional arrange-
ments.[3] The low-dimensional crystal structure may be very
important for some special magnetic materials, such as un-
conventional magnetic instability, ground-state order, spin-
lattice coupling, halogen-mediated exchange, incommensu-
rate magnetic ordering, and so on, in a metal oxide halo-
[a] State Key Laboratory of Structural Chemistry, Fujian Institute
of Research on the Structure of Matter, Chinese Academy of
Sciences,
[9e]
and neodymium like Pb6Cu(AsO3)2Cl7 and Nd5(AsO3)4-
Fuzhou 350002, P. R. China
Cl3,[9f] and oxoarsenate(III) oxide chloride compounds[10]
of lead and some rare-earth elements like Ln3(AsO3)2OCl
(Ln = La, Sm, Gd)[10a] and Pb8Cu(AsO3)2O3Cl5.[10f] Herein
we report two indium oxide halogenide compounds that
contain lone-pair As3+, In2(As2O5)Cl2 (1) and In4(As2O5)-
Fax: +86-591-8371-4946
E-mail: gcguo@fjirsm.ac.cn
[b] Graduate School of Chinese Academy of Sciences,
Beijing 100039, P. R. China
Supporting information for this article is available on the
WWW under http://dx.doi.org/10.1002/ejic.201100091.
Eur. J. Inorg. Chem. 2011, 4069–4076
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(As3O7)Br3 (2). Indium ions in 2 adopt three different coor- Table 2. Atomic coordinates and equivalent isotropic displacement
parameters [Å2].
dination geometries, and UV/Vis/NIR diffuse reflectance
[a]
spectroscopy as well as band structure calculations show
that they are wide-band-gap semiconductors.
x
y
z
Ueq
1
In1
In2
As1
As2
Cl1
Cl2
O1
O2
O3
O4
O5
0.59956(10)
0.14796(10)
0.10931(15)
0.29837(15)
0.7642(4)
0.2485(4)
0.1648(9)
0.30445(8)
0.22570(9)
0.15471(12) 0.24572(12) 0.0120(3)
0.77117(12) 0.20106(12) 0.0121(3)
0.3881(3)
0.2895(3)
0.7318(8)
0.2121(8)
0.0381(9)
0.3794(9)
0.0941(8)
0.47609(9)
0.66220(9)
0.0128(2)
0.01236(19)
Results and Discussion
Structure Description
0.2806(3)
0.9576(3)
0.3421(8)
0.6506(7)
0.2656(8)
0.3850(8)
0.3961(8)
0.0189(7)
0.0255(8)
0.0120(17)
0.0129(19)
0.0192(18)
0.0177(19)
0.0130(18)
Compounds 1 and 2 crystallize in the triclinic system
¯
with space group P1. Experimental parameters, atomic co-
0.4638(9)
0.3385(10)
0.3145(10)
0.0045(10)
ordinates, and selected interatomic distances are listed in
Tables 1, 2, and 3, respectively. They both show layered
structures but have totally different building blocks.
2
Table 1. Crystal data and structure refinement parameters.
In1
In2
In3
In4
In5
As1
As2
As3
As4
As5
Br1
Br2
Br3
O1
O2
O3
O4
O5
O6
O7
O8
O9
0.0000
0.0000
0.5000
0.0000
0.21023(9)
0.29032(9)
0.19910(10) 0.52284(9)
0.0000
0.0000
0.01313(8)
0.01227(8)
0.0118(3)
0.0119(3)
0.0121(2)
0.0124(2)
0.0216(3)
1
2
0.25950(11)
0.65161(11)
0.15362(13)
0.02775(16)
0.25471(17)
0.62440(16)
0.92460(17)
0.39772(17)
0.0988(2)
Chemical formula
Mr
Crystal size [mm]
Crystal system
Space group
a [Å]
b [Å]
c [Å]
α [°]
β [°]
In2(As2O5)Cl2
530.38
0.10ϫ0.05ϫ0.01 0.15ϫ0.10ϫ0.02
In4(As2O5)(As3O7)Br3
1265.61
0.67955(13) 0.19629(11) 0.0119(3)
0.37816(13) 0.22828(12) 0.0137(3)
0.47832(13) 0.18240(11) 0.0127(3)
0.08979(14) 0.25407(12) 0.0145(3)
0.00754(13) 0.81718(12) 0.0131(3)
0.64462(18) 0.55427(16) 0.0403(4)
0.03008(18) 0.41125(15) 0.0383(4)
0.32329(19) 0.52747(18) 0.0464(5)
0.3456(9)
0.0815(8)
0.4075(8)
0.8051(8)
0.3856(9)
0.6384(8)
0.5606(9)
0.3638(8)
0.1218(9)
0.0873(8)
0.0833(9)
0.1227(8)
triclinic
triclinic
¯
¯
P1
P1
6.6957(12)
7.4580(18)
8.9568(19)
108.434(9)
104.983(2)
102.045(4)
388.77(14)
2
7.998(6)
10.523(6)
11.952(8)
70.92(2)
79.62(2)
80.27(3)
928.5(10)
2
0.2646(2)
0.3889(2)
γ [°]
0.1628(11)
0.2411(10)
0.7762(11)
0.1355(11)
0.4722(10)
0.5620(11)
0.2162(11)
0.0929(11)
0.4986(11)
0.0668(11)
0.0866(13)
0.7282(11)
0.1226(7)
0.9111(7)
0.0829(7)
0.0814(7)
0.1491(8)
0.0847(8)
0.1736(8)
0.8962(7)
0.0708(8)
0.1214(7)
0.6926(8)
0.1781(8)
0.0130(19)
0.0118(19)
0.0128(19)
0.0130(19)
0.0139(19)
0.016(2)
0.0152(19)
0.0130(19)
0.018(2)
V [Å3]
Z
Dcalcd. [gcm–1]
μ [mm–1]
F(000)
4.531
15.031
476
4.527
20.250
1124
θ range [°]
Measd. reflections
Indep. reflections/Rint 1335/0.1125
2.56–25.00
2697
2.06–25.50
6256
3451/0.0572
2628
0.0483
0.1083
Obsd. reflections
827
O10
O11
O12
0.0135(19)
0.022(2)
0.0147(19)
[a]
R1 [IϾ2σ(I)]
0.0630
0.1773
0.975
[b]
wR2 (all data)
GOF on F2
0.970
1.476/–1.829
Δρmax/Δρmin [eÅ–3]
2.495/–2.739
[a] Ueq is defined as one-third of the trace of the orthogonalized
Uij tensor.
[a] R1 = ||Fo| – |Fc||/|Fo|. [b] wR2 = [w(F2o – Fc2)2]/[w(F2o)2]1/2
.
Compound 1 is the first oxoarsenate(III) chloride of in- dium oxochloride layer (Figure 1). Meanwhile, atoms As1
dium, in which there are two crystallographically indepen- and As2 are located between the ring chains and consoli-
dent indium atoms, as shown in Figure S3a in the Support- date the interlinkage of chains through the formation of
ing Information. The In1 atom is coordinated by five oxy- (As2O5)4– anions (Figure 2). The layers are stacked parallel
gen atoms with the bond lengths ranging from 2.084(7) to along the c direction to yield the crystal structure of 1 (Fig-
2.244(5) Å and by one chlorine atom with the bond length ure 3).
of 2.464(3) Å, to form a distorted [In1O5Cl] octahedron,
There are five crystallographically different indium
two of which share edges with each other to form an In1 atoms in 2 (Figure S3b in the Supporting Information).
octahedral dimer. The In2 atom is also octahedrally coordi- Atoms In1, In2, and In3 are all octahedrally coordinated
nated by four oxygen atoms with bond lengths in the range by six oxygen atoms to form distorted [InO6] octahedra,
2.124(6)–2.219(6) Å and by two chlorine atoms with bond which share edges with each other to form a 1D zigzag In
lengths of 2.666(2) and 2.414(3) Å, respectively, to form a octahedral chain that extends along the b direction (Fig-
distorted [In2O4Cl2] octahedron, two of which also share ure 4). All the chains are edge- and corner-connected by
edges with each other to form an In2 octahedral dimer. Two distorted unicapped trigonal prism (In4O7), in which the
In1 octahedral dimers are double-bridged by two In2 atoms atom In4 is coordinated by seven oxygen atoms, to form a
to form a 12-membered ring; they share the In1 octahedral 2D indium oxide layer. The In–O bonds in [InO6] and
dimers with each other to form a ring chain along the a [InO7] range from 2.110(8) to 2.341(8) Å, which lie in the
direction. The ring chains are interlinked through the In2 normal range for In–O bond lengths in known indium ox-
octahedral dimers along the b direction to form a 2D in- ides.[11] Meanwhile, atoms As1, As2, and As3 locate be-
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Indium Arsenic(III) Oxide Halides
Table 3. Select bond lengths [Å].[a]
1
In1–O1#1
In1–O4
In1–O4#1
In1–O2
In1–O3
In1–Cl1
In2–O5
2.084(6)
2.133(7)
2.156(6)
2.213(7)
2.244(5)
2.464(3)
2.124(6)
2.166(7)
2.175(6)
2.219(6)
2.414(3)
2.666(2)
1.756(5)
As1–O5
As1–O3
As2–O2#1
As2–O1
As2–O3#5
O1–In2#3
O2–In2
O3–As2#4
O3–As1
O3–In1
O4–In1#1
O5–In2
O5–In2#2
1.804(8)
1.912(7)
1.742(6)
1.786(7)
1.827(6)
2.175(6)
2.166(7)
1.827(6)
1.912(7)
2.244(5)
2.156(6)
2.124(6)
2.219(6)
In2–O2
In2–O1#3
In2–O5#2
In2–Cl2
In2–Cl1#1
As1–O4
2
Figure 1. An indium–oxoarsenic–chloride layer parallel to the ab
plane in 1. Arsenic atoms are omitted for clarity.
In1–O3#6
In1–O3#8
In1–O8#7
In1–O8#10
In1–O1
In1–O1#5
In2–O10
In2–O10#4
In2–O4#5
In2–O4#12
In2–O2#10
In2–O2#11
In3–O9
In3–O2#10
In3–O10
In3–O8#10
In3–O1
In3–O6#6
In4–O6#6
In4–O3
In4–O4#6
In4–O9
2.110(8)
2.110(8)
2.148(8)
2.148(8)
2.213(9)
2.213(9)
2.133(8)
2.133(8)
2.156(9)
2.156(9)
2.192(8)
2.192(8)
2.110(9)
2.135(8)
2.142(8)
2.192(8)
2.196(8)
2.212(8)
2.130(9)
2.151(8)
2.152(8)
2.178(9)
2.281(9)
2.341(8)
2.439(9)
2.025(9)
2.483(2)
In5–Br1#7
In5–Br2
As1–O4
As1–O8#7
As1–O7
As2–O1
As2–O7
As2–O5
As3–O6
As3–O3
2.487(2)
2.514(2)
1.774(8)
1.796(8)
1.830(8)
1.719(8)
1.805(9)
1.825(8)
1.758(9)
1.788(8)
1.850(8)
1.734(9)
1.782(8)
1.881(9)
1.777(10)
1.780(8)
1.814(8)
2.196(8)
2.135(8)
2.156(9)
1.850(8)
2.341(8)
2.130(9)
2.212(8)
2.192(8)
2.142(8)
1.881(9)
As3–O5
As4–O11#9
As4–O10#1
As4–O12
As5–O9#9
As5–O2
As5–O12#9
O1–In3
O2–In3#2
O4–In2#3
O5–As3
O5–In4
Figure 2. Four 12-membered indium oxide rings are clamped to-
gether by (As2O5)4– anions. Chlorine atoms are omitted for clarity.
In4–O12
In4–O5
In4–O7#6
In5–O11
In5–Br3
O6–In4#6
O6–In3#6
O8–In3#2
O10–In3
O12–As4
[a] Symmetry codes: compound 1: (#1) –x + 1, –y + 1, –z + 1;
(#2) –x, –y, –z + 1; (#3) –x, –y + 1, –z + 1; (#4) x, y – 1, z; (#5)
x, y + 1, z. compound 2: (#1) x + 1, y, z; (#2) x, y, z + 1; (#3) x,
y + 1, z; (#4) –x, –y, –z (#5) –x, –y + 1, –z (#6) –x + 1, –y + 1,
–z (#7) –x, –y + 1, –z + 1 (#8) x – 1, y, z (#9) –x + 1, –y, –z + 1
(#10) x, y, z – 1 (#11) –x, –y, –z + 1 (#12) x, y – 1, z.
tween the zigzag In octahedral chains and consolidate the
interlinkage of chains through the formation of (As3O7)5–
anions (Figure 5, a). The (As2O5)4– anions, built of three
coordinated As4 and As5 atoms, clamp the In2 atoms and
also play a role in consolidating the interlinkage of zigzag
chains (Figure 5, b). The O11 atoms coordinated to As4
Figure 3. View of the crystal structure of 1 along the a direction.
There are three different indium-ion coordination geo-
protrude outside the indium oxide layer, whereas other oxy- metries in 2: octahedrally coordinated In1, In2, and In3
gen atoms are located inside the indium oxide layers. Atom ions, seven-coordinate In4 ions, and tetrahedrally coordi-
O11 is also coordinated to atom In5, which is also tetrahe- nated In5 ions. Compound 2 is the first compound to con-
drally coordinated by other three bromine atoms with an tain three different indium-ion coordination geometries.
average In–Br bond length of 2.495(2) Å. The layers are
The two compounds both contain an arsenic-oxide
stacked parallel along the c direction to yield the crystal group (As2O5)4–, which is composed of two corner-sharing
structure of 2 (Figure 6).
[AsO3E] (E = lone pair). In 1, four of the five oxygen atoms
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in the metal–oxoarsenate(III) system. The only known ex-
amples are Eu3Zn(As3O7)(AsO3)2 and Eu6Fe5(As4O9)2-
(As3O7)2(AsO3)2.[12] The (As2O5)4– ion can be found in a
metal–oxoarsenate(III) system,[13] but only Pb8(As2O5)2-
[9e]
OCl6
in metal–oxoarsenate(III)–halide system has been
reported. Five of the seven oxygen atoms of each (As3O7)5–
ion (O1, O3, O4, O6, and O8) are bonded to two indium
atoms, and the remaining two (O5 and O7) to only one
(Figure 7, c). The As–O bond lengths in the (As2O5)4– and
(As3O7)5– ions in the two compounds range from 1.719(8)
to 1.912(7) Å, which are close to those found in the litera-
ture.[9,10]
Figure 4. A 2D indium oxide layer parallel to the ab plane in 2.
Arsenic atoms and [In5Br3O] units are omitted for clarity.
Figure 7. Coordination of (a) (As2O5)4– in 1, (b) (As2O5)4– in 2,
and (c) (As3O7)5– in 2. Yellow sphere: indium.
The lone pairs E and the halogen ions are located toward
the space available between the In–O layers in 1 and 2, and
these compounds provide new examples in which lone-pair–
lone-pair and lone-pair–halogen interactions are observed.
The effect of the clusterization of lone electron pairs of
As3+ cations in 1 and 2 plays a very important role in bring-
ing the layers together. Each layer can thus be considered
an infinite two-dimensional molecule. On the other hand,
layer-structure compounds 1 and 2 can be regarded as
quantum well materials and may be potentially applied in
diode lasers and photodetectors.
Figure 5. Two zigzag chains are consolidated by (a) two (As3O7)5–
anions and also by (b) two (As2O5)4– anions that clamp In2.
Thermogravimetric Analyses (TGA)
TGA curves indicate that compounds 1 and 2 are stable
up to about 500 and 530 °C, respectively (Figure 8). They
both exhibit two main steps of weight losses. For 1, the first
one occurred in the temperature range of 500–640 °C,
which corresponds to the release of 0.78 molecule of As2O3
and 0.43 molecule of AsCl3. The observed weight loss and
calculated value are both 44.0%. Above 650 °C, it is further
decomposed, which corresponds to the release of 0.24 mole-
cule of InCl3. The total weight loss at 1000 °C is 55.0%,
Figure 6. View of the crystal structure of 2 along the a direction.
of each (As2O5)4– anion (O1, O2, O4, and O5) are bonded which agrees with the calculated value of the final residue
to two indium atoms, the remaining one (O3) to only one In2O3 (46.1%). The final residue In2O3 can be identified by
(Figure 7, a). The (As2O5)4– anion in 2 has a similar config- powder XRD (Figure S4 in the Supporting Information)
uration to that in 1 but has a different coordination envi- and energy-dispersive X-ray spectroscopy (EDS). The EDS
ronment. Three oxygen atoms (O2, O9, and O10) are measurements of the final residues of 1 and 2 show that
bonded to two indium atoms, and two oxygen atoms (O11 both of them contain only elements oxygen and indium in
and O12) are bonded to only one indium atom (Figure 7, a ratio of about 3:2. The first decomposition step of 2 oc-
b). Another type of arsenic-oxide group, (As3O7)5–, also ex- curred in the temperature range of 530–650 °C, which cor-
ists in 2. Three polyhedral [AsO3E] corner-share with each responds to the release of one As2O3 and AsBr3. The ob-
other to form a V-type (As3O7)5– polyanion, which is rare served weight loss (40.8%) is close to the calculated value
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