Crystal structures and thermal behaviour of double complex compounds incorporating the [Cr{CO(NH2)2}6]3+ cation

Article abstract of DOI:10.1016/j.molstruc.2017.06.099

Double complex compounds (DCC) of the [Cr(ur)₆][Fe(CN)₆]^·4H₂O (I), [Cr(ur)₆][Co(CN)₆]·4H₂O (II), [Cr(ur)₆][Fe(Ox)₃]·2H₂O (III), and [Cr(ur)₆][Co(Ox)₃].3.5H₂O (IV) composition, where ur is CO(NH₂)₂, Ох – С₂О₄^2? have been synthesized and their crystal structures have been studied. The DCC I, II and IV are triclinic (Р-1); III is orthorhombic (С222₁). The DCC thermal behavior in air and argon atmospheres was analyzed by the following parameters: the temperature interval of total decomposition and the nature of gaseous and solid products. The end solid products in air were FeO and FeCr₂O₄ for I, a mixture of СоCr₂O₄ + Со₂CrO₄ for II and IV and an X-ray amorphous phase with composition CrFeO_2.5 for III. The gaseous products were HCN, NH₃, HNCO, N₂O, СО, СО₂, N₂, and urea. The temperatures of total decomposition in air were: I, II 400°С, III – 350°С, IV – 460°С. In argon, the solid residue contained, besides the oxides, 7–30% of carbon up to 1000°С.

Full text of DOI:10.1016/j.molstruc.2017.06.099

Accepted Manuscript
Crystal structures and thermal behaviour of double complex compounds incorporating
3+
the [Cr{CO(NH ) } ] cation
2 6
2
S.I. Pechenyuk, А.А. Zolotarev, A.N. Gosteva, D.P. Domonov, А.А. Shimkin
PII:
S0022-2860(17)30880-3
10.1016/j.molstruc.2017.06.099
MOLSTR 23985
DOI:
Reference:
To appear in: Journal of Molecular Structure
Received Date: 30 March 2017
Revised Date: 20 June 2017
Accepted Date: 20 June 2017
Please cite this article as: S.I. Pechenyuk, А.А. Zolotarev, A.N. Gosteva, D.P. Domonov, А.А.
Shimkin, Crystal structures and thermal behaviour of double complex compounds incorporating the
3+
[
Cr{CO(NH ) } ] cation, Journal of Molecular Structure (2017), doi: 10.1016/j.molstruc.2017.06.099.
2
2 6
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ACCEPTED MANUSCRIPT

ACCEPTED MANUSCRIPT
Crystal structures and thermal behaviour of double complex compounds incorporating the
3
+
[
Cr{CO(NH ) } ] cation
2 2 6
a
b
a
a,*
c
Pechenyuk S.I. , Zolotarev А.А. , Gosteva A.N. , Domonov D.P. , Shimkin А.А.
a
I.V.Tananaev Institute of Chemistry and Technology of Rare Elements and Mineral Raw Materials of the Kola
Science Center, RAS, Akademgorodok 26a, Apatity, Russian
b
Saint Petersburg State University, Saint Petersburg, Russian
c
All-Russia Research Institute of Aircraft Materials, Moscow, Russian
*
Corresponding author.
.
.
Abstract. Double complex compounds (DCC) of the [Cr(ur) ][Fe(CN) ] 4H O (I), [Cr(ur) ][Co(CN) ] 4H O (II),
[
6
6
2
6
6
2
.
.
2-
Cr(ur) ][Fe(Ox) ] 2H O (III), and [Cr(ur) ][Co(Ox) ] 3.5H O (IV) composition, where ur is CO(NH ) , Ох – С О
6 3 2 6 3 2 2 2 2 4
have been synthesized and their crystal structures have been studied. The DCC I, II and IV are triclinic (Р-1); III is
orthorhombic (С222 ). The DCC thermal behavior in air and argon atmospheres was analyzed by the following
1
parameters: the temperature interval of total decomposition and the nature of gaseous and solid products. The end
solid products in air were FeO and FeCr O for I, a mixture of СоCr O + Со CrO for II and IV and an X-ray
2
4
2
4
2
4
amorphous phase with composition CrFeO2.5 for III. The gaseous products were HCN, NH , HNCO, N O, СО,
3
2
СО , N , and urea. The temperatures of total decomposition in air were: I, II 400°С, III – 350°С, IV – 460°С. In
2
2
argon, the solid residue contained, besides the oxides, 7-30% of carbon up to 1000°С.
Key words: double complex compound, thermolysis, crystal structure, X-ray diffraction, IR spectroscopy
1
.
Introduction
Thermal decomposition of various complex compounds is now recognized as a promising
technique in the production of composite materials of which many are unobtainable otherwise.
An example of such composites are metastable bimetallic or metal-carbon systems. One of the
best precursors in the synthesis of these composites are double or heteronuclear complex
compounds (DCC). We have investigated the DCC of the [M L ] [M X ] type, where M and
1
a x
2
b y
1
M are metals, L are neutral ligands, and X are acidoligands, as precursors for the synthesis of
2
bimetallic materials [1]. Thermolysis is a process which allows to remove the ligands from DCC
by way of careful heating. Thermolysis in general is represents a complex solid-phase process
involving redox and substitution reactions both within the solid phase and at the interfaces, and
the formation of new solid phases and interfaces. The formation of new solid phases is attended
by either the formation of a porous structure or residue crystallization and releasing of gaseous
products from the solid phases. The purposeful synthesis of a certain product requires
information about all thermolysis stages. Thus, it is important to know the crystalline structure of
initial and intermediate products because both the formation of new solid phases and gas release
are related to the movement (diffusion) of atoms within the solid phase and across the interfaces.
3
+
3-
Complexes containing the [Cr{CO(NH ) } ] (CO(NH ) – urea) cation and [M(CN) ]
2
2 6
2 2
6
3
-
and [M(C О ) ] anions have been known for a long time [2] but, to our knowledge, there is no
2
4 3
evidence on their crystal structure and thermal bеhavior. Interestingly, the thermal

ACCEPTED MANUSCRIPT
decomposition of these DCC produces highly dispersed chromospinel, pseudochromite and
mixed oxides.
The aim of this work is to study the crystal structures, characterize the properties, and
perform a comparative analysis of the thermal decomposition procedure of DCC
.
.
.
[
[
Cr(ur) ][Fe(CN) ] 4H O (I), [Cr(ur) ][Co(CN) ] 4H O (II), [Cr(ur) ][Fe(Ox) ] 2H O (III),
6 6 2 6 6 2 6 3 2
.
Cr(ur) ][Co(Ox) ] 3.5H O (IV), including the nature of resulting solid and gaseous products.
6
3
2
2
. Experimental
2
.1. Synthesis
DCC I-II were synthesized from hexaureachromium(III)–chloride [Cr(ur) ]Cl ⋅3H O
6
3
2
obtained according to [3] by means of mixing a water solution with an equivalent quantity of a
cation complex and commercial potassium hexacyanoferrate or hexacyanocobaltate (chemically
pure), and DCC III-IV by means of mixing a solution of the same cation complex with
potassium (tris)oxalatoferrate or (tris)oxalatocobaltate obtained according to [3]. For example,
1
1.45 g (0.02 mol) [Cr(ur) ]Cl ⋅3H O and 6.58 g (0.02 mol) К [Fe(CN) ] were dissolved in a
6 3 2 3 6
minimal volume of water and blended. This resulted in immediate precipitation of bright-green
lamellar crystals, which were filtered and washed with water and ethanol, then dried in a
desiccator over alkaline pellets. The yield of I was 12.85 g, or 95% of the theoretical value; for
II, III and IV it was 98, 99, and 63%, respectively. Complex IV is probably more soluble in
comparison to 3 other compounds.
2
.2. Physical measurements
The DCC were characterized using the XRD, IR spectroscopy. Metals in the DCC were
analyzed using an AАnalyst 400 spectrometer in DCC solutions in aqua regis. Analysis for
carbon contents was performed at an ELTRA CS-2000 automatic analyzer (Table 1). The
powder XRD analysis of the DCC was performed using a Shimadzu XRD 6000 diffractometer
(
CuK radiation, graphite monochromator). The powder diffraction patterns of the synthesis
α
products correlated with theoretical patterns calculated from the structural data, also revealing
monophasity of the products obtained.(Supplementary)
The IR spectra were recorded using a Nicolet 6700 FT-IR spectrometer in the region of
-1
4
000-400 сm in KBr tablets. The IR spectroscopic studies in the DCC identification were based
-1
on [4-6]. IR-spectrum I (ν, cm ): ν(OH ) (3440); ν(NH ) (3380, 3220); ν(C≡N) (2115); δ(OH )
2
2
2
(1640); δ(NH ) (1560); ν(C-O) (1510); ρ (NH ) (1140); ν(C-N) (1040); δ(NCO) (630); δ(NCN)
2 w 2
(540).
2

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-1
IR-spectrum II (v, cm ): ν(OH ) (3450); ν(NH ) (3350, 3220); ν(C≡N) (2140); δ(OH ) (1640);
2
2
2
δ(NH ) (1560); ν(C-O) (1500); ρ (NH ) (1140); ν(C-N) (1030); δ(NCO) (760); δ(NCN) (530);
2
w
2
ν(M-C) (400).
-1
IR-spectrum III (ν, cm ): ν(OH) (3580); ν(OH ) (3470); ν(NH ) (3420, 3210); ν (C=O) (1680);
2
2
as
δ(NH ) (1560); ν(C-O) (1500); ν (C-O)+ ν(C-C) (1370); ν (C=O)+ δ(O-C=O) (1260, 1220);
2
s
s
ρ (NH ) (1150); ν(C-N) (1020); ν (C-O)+ δ(O-C=O) (880); δ(O-C=O)+ ν(M-O) (780); δ(NCN)
w
2
s
(540).
-1
IR-spectrum IV (ν, cm ):
ν(NH ) free (3463, 3346); ν(NH ) bound (3232); ν (C=O) (1708,
2
2
as
1
671); δ (NH ) (1632); ν(C=O) (1558); ν(C - N) (1500, 1385); ν (C-O) + δ(O-C=O) (1243);
as 2 δ
ρ (NH ) (1156); ν (C-N) (1034); ν (C-O) (900); ρ(OH ) (849); δ(O-C=O) + ν(M-O) (822, 804);
w
2
s
s
2
ω(C-O) (770); ρ(OH ) (630); ν(M-O) + ν(C-C) (559); ν(M-O) + δcycl (444).
2
2
.3. The X-ray structure analyses
The X-ray structure analyses of DCC were conducted at the temperature of 100 К using
an Agilent Technologies Excalibur Eos (for II, III, IV) and SuperNova (for I) single-crystal
diffractometers equipped with a flat CCD detector. The crystallographic data and some
refinement parameters of DCC structures are presented in Table 2. The structures were solved by
direct methods and refined by means of the SHELX software [7] incorporated in an OLEX2
program complex [8]. The absorption correction was applied in the CrysAlisPro software
package [9] empirically, using the spherical harmonics implemented in the SCALE3 ABSPACK
scaling algorithm.
Hydrogen atoms were included in the refinement with fixed positional and temperature
parameters (in the `riding` model approximation according to the SHELX algorithms), with
U (H) set to 1.2U (N) and N–H 0.86 Å for NH groups, U (H) set to 1.5U (O) and O–H 0.85
iso
eq
2
iso
eq
Å for H O molecules. The CIF files containing the structural information have been deposited in
2
CCDC № 1517429, 1487604, 1487605 and 1487603 for I, II, III, IV and are available in the
database
www.ccdc.cam.ac.uk/data_request/cif.
.4. Thermal analyses
The thermal analyses in air and argon atmospheres were performed using a NETZSCH
of
organic
compound
crystal
structures
at
the
site
2
STA 409 PC/PG device in a covered corundum crucible, with a weight of 6-10 mg and a heating
rate of 10 deg/min. The thermographs of the complexes can be seen in Figures 4, 5. For a larger
weight (~0.5 g), thermolysis was carried out in a quartz tube reactor inserted into a tube furnace
SNOL -02/1250. The IR spectra of gaseous products of thermolysis were analyzed on a Netzsch
STA 449 F3 Jupiter simultaneous thermal analyzer combined with a Bruker Tensor 27 FTIR
3

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spectrometer. Weighed samples of 17-25 mg was heated in the corundum crucible in a nitrogen
atmosphere (99.999%) or synthetic air in a temperature range of 40–1000°С. The heating rate
1
1
–
–
was 10°C min . IR spectra were recorded in a range of 550–4000 cm with a resolution of 4
1
–
cm and averaging over 32 scans. The compounds were identified by comparing with the NIST
database. The contents of CO and CO were determined using a MAG gas analyzer
2
(”MONITORING”JSC, Saint-Petersburg, Russia). The quantity analysis of the gaseous products
of thermolysis (GPT) was performed in the following way: the tube reactor output was supplied
with two Drecksel vessels with stripping solutions were sequentially put, the first one containing
0
.1M HCl, the second - 0.15 M NaOH + 0.25 M H O heated to 80°C. The first solution
2 2
-
absorbed ammonia, the second – HCN, HNCO, N O with nitrogen oxidation to NO , which was
2
3
then determined in the solution (Table 3).
3
.
Results and discussion
.1. Description of crystal structures
The DCC I, II and IV are triclinic (Р-1); III – is orthorhombic (С222 ) (Table 2). All
3
1
four DCC structures are described as the structures with isolated anion and cation complexes.
The structural units and packing are presented in Figures 1, 2 and 3 by the example of
compounds II, III and IV respectively. The compounds I and II are isostructural. All central
metal ions in the studied DCC have the coordination number 6 and the coordination of
chromium, iron and cobalt atoms is represented as almost regular octahedra. The cation
octahedron consists of six oxygen atoms of six urea molecules, with average Cr-O bond length
equal 1.966 Å. The arrangement of anion include six carbon atoms of six cyano groups, with
average bond lengths Fe-C and Co-C equal 1.940 and 1.899 Å for I and II, respectively, and six
oxygen atoms of three oxalate ions with average bond lengths Fe-O and Co-O equal 2.011 Å and
1
.897 Å for III and IV respectively. Figures 1b, 2b and 3b show a packing of complex cations
and anions in the structures. As noted before, compounds I and II are isostructural, with 1 anion
and 1 cation per one unit cell between which 4 water molecules (2 crystallographically
independent water molecules) are located. One unit cell of compound III contains 4
crystallographically equivalent anions, 4 crystallographically equivalent cations and 8 water
molecules (1 crystallographically independent water molecule). In the one unit cell of compound
IV there are 2 crystallographically equivalent anions, 2 crystallographically independent cations
and 7 water molecules (3.5 crystallographically independent water molecules). The structural
units of the compounds (cations, anions and water molecules) are interconnected by hydrogen
and intermolecular bonds (Figures 1, 2, 3). The length of the shortest hydrogen contact D‰A for
4

ACCEPTED MANUSCRIPT
I is 2.882(4) Å; for II - 2.893(3) Å; for III - 2.746(4) Å; and for IV - 2.783(4) Å. All these
structures are based upon isolated anion and cation complexes. The anion and cation octahedra
are practically undistorted, that seems characteristic of this DCC type.
3
.2. Thermal behavior of DCC
Examination of thermal analysis curves for DCC I and II in the air atmosphere has
revealed that these compounds decompose similarly (Fig. 4a). The outersphere water releases up
to ~140°C, which is attended by a small endothermal effect at 100°C. From 120 to 200°C, no
mass loss is observed, i.e. the dehydrated complex is stable. Most of the mass is lost between 200
to 400°C as a result of which the residues of calcination correspond to a mixture of
FeO+FeCr O (chromite) for I and a mixture СоCr O + Со CrO for II [10].
2
4
2
4
2
4
As revealed by qualitative analysis of GPT, there is a connection between the observed
effects and the nature of occurring transformations. An example for DCC I is presented in Figure
4
b. It shows the onset of a simultaneous emission of HCN, NH , HNCO and N O traces at 175°C
3 2
continuing until ~400°С. At ~ 250°С, this process is supplemented by the CO emission
2
continuing until ~425°C. According to [11], NH and HNCO are the urea decomposition products
3
and HCN is the product of complex anion decomposition. The HCN emission ends already at
3
25°C. Since the formation of the main mass of HCN, NH and HNCO is not accompanied by
3
intensive CO emission, the CO is mainly the product of residual ligands oxidation. It is evident
2
2
that the thermal decomposition of the DCC cation and anion proceeds simultaneously but not
sequentially, i.e. anion after cation, as it might be expected from the literature data about the
cationic and anionic complexes thermolysis [12-14].
In the cases DCC II-IV except on products of urea decomposition, escaping of urea per se
is sometimes observed. This is confirmed by static experiments including a quantity analysis of
GPT at thermolysis of DCC II in air (Table 3). A part of urea escapes in a free state (~1 mmol).
The content of C in the solid residue is negligibly small. We managed to collect 79% C and 55%
N from the total content. Hence it is assumed that a part of C escapes as CO and a part of N - as
N .
2
The same similarity of thermal analysis curves for DCC I and II was observed in inert
atmosphere (Fig. 4c). An endothermal effect, attended by outersphere water removal, also
emerged in argon and nitrogen atmospheres at 100°C. In argon, as it was in air, achieving of
2
00°C was marked by a second endoeffect, although latter was greater than in air. Between 200-
00°C, there was observed a stepless throw of TG and DSC curves without clear thermal effects.
6
Only at 600-700°C, we recorded a crucial mass loss caused by nitrogen emission detected by
5

ACCEPTED MANUSCRIPT
analysis of the intermediate products analysis. The composition of GPT in inert atmosphere is
qualitatively the same as in air, but the product ratio is different (Fig. 4d). The emissions of HCN,
NH and HNCO also begin simultaneously at 200°C, but the temperature range of HCN broadens
3
up to 500°C and the signal intensity of HNCO is greater than that of ammonia. Only traces of CO2
were obtained. In addition, much of the urea escaped. The residues of calcination of I and II were
found to contain, respectively, Fe O (magnetite)+FeCr O (chromite)+С
and Со + Cr O +
2 3
3
4
2
4
amorph.
CoCrO (orthorhombic pseudochromite)+ Camorph [10] .
4
These findings correlate with the result of GPT II analysis (Table 3). 28% C persist in the
solid residue. No CO emission was observed. The other GPT must be urea, CO and N .
2
2
The thermal behavior of DCC III and IV, which are similar in composition but not in
structure, differs substantially both from each other and from that of I and II. In air, up to 150
(III) and 250°C (IV), the TG-DSC curves (Fig. 5a) did not demonstrate any clear effects of
outersphere water removal. Beginning with ~160°C, both complexes simultaneously released NH3
and CO (Fig. 5b). Between 210 and 300°C, CO did not escape. More intensive CO peaks
2
2
2
appeared in the range of 300-360 (III) and 330–450°C (IV) with great exoeffects at 320 and
40°C, respectively. Since the second CO peak was attended by N O emission, these effects were
4
2
2
attributed to the oxidation of remaining coordinated ligands. The CO emission at around 160°C is
2
the result of partial decomposition of the coordinated oxalate ions because urea does not
decompose at this temperature [11]. The products of III thermolysis in air did not contain urea,
and the gaseous phase analysis indicated CO emission peaks simultaneous with CO . The
2
decomposition of III and IV terminated at 400 and 500°C, respectively. The final products of
thermolysis in air were an X-ray amorphous phase with composition CrFeO for III and СоCr O
4
2
.5
2
+
Со CrO for IV [10].
2 4
Quantitative analysis of GPT IV in air has revealed the following (Table 3). Summarily,
we managed to collect 98% N and 98% C. The residues of calcination in argon for III and IV
were FeO+FeCr O (chromite)+С and Со + Cr O + C respectively.
2
4
amorph.
2
3
amorph,
The thermal analysis curves of DCC III and IV in argon coincided up to 200 (III) and
50°C(IV) with appropriate curves observed in air (Fig. 5c). Then decomposition process
2
occurred without clear thermal effects up to 1000°C. CO was emitted in 6 steps. The first step
2
was observed at ~175°C, the next 5 steps were weaker than the first one, and the last effect was
observed at 750°C(Fig. 5d). The emission of NH and HNCO began simultaneously with CO , but
3
2
terminated at~400°C. The emission of CO was attended CO for both DCC, the ratio CO:CO ≅ 2:1,
2
2
as in the previous paper [15].
6

ACCEPTED MANUSCRIPT
Quantitative analysis of GPT IV in argon has revealed the following (Table 3). Summarily,
we managed to collect 57% N as NH and 23% as HNCO and 23% C as HNCO and 34% as CO .
3
2
1
2% C was persisted in the residue of calcination. The remainder C was probably emitted as CO.
4
. Conclusion
1
. Exploring of the structures and thermal behavior of DCC of the [Cr(ur) ][Fe(Co)X ] type,
6 6
–
2–
4
where X – CN , 1/2C O , has revealed the following. In the first place, it has been established
2
that the isostructural compounds similar in composition behave almost identically, but lead to the
formation of different solid products due to different central ions and ligands. Studies of the
thermal behavior of DCC I-IV afforded to determine the temperature ranges wherein these
gaseous products release. 2. It is established that the thermal decomposition of DCC III in air at
3
50°С produces a finely dispersed (X-ray amorphous) phase CrFeO . In the other cases the
2.5
products are crystalline chromites and pseudochromites. 3. DCC III with an orthorhombic
structure is the least thermally stable. 4. The inner sphere of [Cr(ur) ][Co(C O ) ] (IV) becomes
6
2
4 3
partly destroyed already at 170°С because of decomposition of one of the coordinated C O .
2
4
7

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1] S.V. Коrenev, A.B. Venedictov, Yu.V. Shubin, S.A. Gromilov, K.V. Yusenko, Journal of
Structural Chemistry. 44 (2003) 46-59.
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Chemie GmbH, 32.
3] G. Brauer, Handbuch der Präparativen Anorganischen Chemie: in Drei Bänden / G. Brauer –
Stuttgart: Ferdinand Enke, 1978. – 2113 p.
4] К. Nakomoto, IR spectra and Raman Spectra of Inorganic and Coordination Compounds. М.:
Mir, 1991.
5] R.B. Penland, S. Mizushima, C. Curran, J.V. Quagliand, J. Amer. Chem. Soc., 79 (1957)
575-1578.
[
[
[
[
1
[
[
[
6] N. Gorska, E. Mikuli, L. Kotai, Eur. Chem. Bull. 3 (2014) 474-481.
7] G.M. Sheldrick, Acta Cryst. 64A (2008) 112-122.
8] O.V. Dolomanov, L.J. Bourhis, R.J. Gildea, J.A.K. Howard, H. Puschmann, J. Appl. Cryst.
4
2 (2009) 339-341.
[
[
9] CrysAlisPro, Agilent Technologies, Version 1.171.36.20 (release 27-06-2012).
10] JCPDS-ICDD card. Newtown Square (PA, USA): International Centre for Diffraction Data,
2
002.
[
[
[
[
11] P.M. Schaber, J. Colson, S. Higgins, J. Brauer, Thermochim. Acta 424 (2004) 131-142.
12] K.S. Rejitha, S. Mathew, J. Therm. Anal. Calorim. 102 (2010) 931-939.
13] N. Rajic, D. Stojakovic, R. Gabrovsek J. Therm. Anal. Calorim. 63 (2001) 191-195.
14] Z. Travnićek, R. Zboril, M.Matikova-Mal’arova, B. Drahoš, J. Černák, Chem.Central
Journal. 7 (2013) 28.
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15] S.I. Pechenyuk, Yu.P. Semushina, N.L. Mikhailova, Yu.V. Ivanov, Rus. J. Coord. Chem. 41
2015) 175-181.
(
8

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Table 1. Data of elemental and crystal optic analyses of DCC I-IV.
DCС
Molecular
mass
Contents, wt.%
Crystal habitus
Crfound
7.7
Crcalc
7.6
Fe/Cofound Fe/Cocalc
Cfound
21.7
Ccalc
20.7
I
695.8
8.1
8.0
anisotropic tabular yellow-green
crystals
II
699.5
768.5
7.5
6.6
7.4
6.7
8.4
7.3
8.4
7.3
22.2
18.1
20.6
18.7
anisotropic light-green tabular crystals
anisotropic tabular crystals, pleochroism
on N’p – greyish-blue, оn N’g - green
anisotropic turquoise needle-shapedе
crystals
III
IV
798.4
6.4
6.5
7.6
7.4
17.8
18.0

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Table 2. The crystallographic data and some refinement parameters for structures I-IV
DCC
Empirical formula
Molecular weight
Crystal system
Space group
a (Å)
I
II
III
IV
C H N O CrFe
C H N O CrCo
12 32 18 10
C H N O CrFe
12 28 12 20
C H N O21.5CrCo
12 31 12
1
2
32 18 10
696.40
699.48
triclinic
768.31
orthorhombic
C2221
798.42
triclinic
triclinic
P-1
P-1
P-1
7.2347(5)
9.5815(6)
10.4223(7)
97.774(5)
91.278(5)
94.734(5)
712.97(8)
1
7.2499 (5)
9.5303(7)
10.4286(9)
97.681(7)
91.850(6)
94.328(6)
711.39(10)
1
9.0326(6)
21.2902(14)
15.4349(13)
90
11.5268(7)
12.3506(11)
13.3178(8)
96.695(6)
113.644(6)
114.182(7)
1492.2(3)
2
b (Å)
c (Å)
α (°)
β
(°)
90
γ (°)
90
3
V (Å )
2968.2(4)
4
Z
3
Dcalc (g/cm )
1.622
7.932
1.633
1.044
1.719
1.777
–
1
µ (mm )
0.958
1.030
F(000)
360.0
361.0
1576.0
820.0
3
Crystal size(mm )
Radiation
0.25 × 0.19 × 0.11
CuKα
0.26 × 0.23 × 0.15
MoKα
0.23 × 0.18 × 0.15
0.28 × 0.24 × 0.15
MoKα
MoKα
Reflexes total/independent
6490/2813
6288/3269
10382/3396
12103/6813
Measuring area 2
°)
θ
8
.57-144.99
5.44-54.99
5.56-54.99
6.04-55.00
(
-
11 ≤ h ≤ 11, -27 ≤
-
≤
8≤ h ≤6, -11≤ K
11, -12≤ l ≤12
0.0632
-9 ≤ h ≤ 9, -12 ≤ k ≤
12, -13 ≤ l ≤ 13
-14 ≤ h ≤ 13, -15 ≤ k
≤ 16, -15 ≤ l ≤ 17
Index range
k ≤ 27, -20 ≤ l ≤ 20
0.0534
Rint
0.0345
0.0356
0.0845
0.0445
0.0930
1.045
0.0308
0.0380
0.0897
0.0495
0.0988
1.028
R1 (I ≥ 2σ(I))
0.0470
0.0400
wR (I ≥ 2σ(I))
0.1192
0.0735
2
R1 (all data)
0.0544
0.0511
wR (all data)
0.1275
0.0778
2
S
1.031
1.050
3
ρmin
,
ρmax, e/Å
0.70/-0.92
0.34/-0.42
-
0.41/-0.38
-0.014(14)
0.56/-0.53
-
Flack parameter
-
2
2 2
2 2 1/2
R = Σ||F | – |F ||/Σ|F |; wR = {Σ [w(F – F ) ]/ Σ [w(F ) ]} ;
1
o
c
o
2
o
c
o
2
2
2
2
2
2
2
1/2
w =1/[σ (F )+(aP) + bP], где P = (F + 2F )/3; s = {Σ [w(F – F )]/(n – p)} where n is the number of
o
o
c
o
c
reflexes and p is the number of refined parameters.
Table 3. The results of quantitative analysis of GTP.
Mmol
DCC Atmo Temperature
%*
C in
solid
residue,
%
o
sphere
range, C
DCC
NH3
N O CO2
2
HCN +
N
C
HNCO
or HNCO
II
air
20-280
0.77
0.3
3.2
2.4
1.1
3.0
4.9
-
-
-
0.1
3.9
-
1.6
4.9
2.9
1.1
1.2
1.7
-
-
2.0
40.3/
54.6
27.5
83.5/
98
67.7/
78.5
17.2
50.6/
98
<0.01
2
80-500
argon
air
20-750
20-300
0.83
0.66
28
<0.1
IV
0.3
0,95
-
3
00-500
argon
20-850
0.72
80.2
57.0
7
*
Nonregistering segregating urea/registering segregated urea

ACCEPTED MANUSCRIPT
a
b
.
Figure 1. Structure of [Cr(ur) ][Co(CN) ] 4H O (II): crystallographically independent part (а);
6
6
2
and packing of complex cations and anions in the structure (projection perpendicular to а axis)
b). The ellipsoids of thermal vibrations are plotted at a probability level of 50%. The hydrogen
bonds are presented as dotted lines.
(

ACCEPTED MANUSCRIPT
a
b
.
Figure 2. The structure of [Cr(ur) ][Fe(Ox) ] 2H O (III): crystallographically independent part
6
3
2
(а); and packing of complex cations and anions in the structure (projection perpendicular to а
axis) (b). The ellipsoids of thermal vibrations are plotted at a probability level of 50%. The
hydrogen bonds are presented as dotted lines.
1
2

ACCEPTED MANUSCRIPT
a
b
.
Figure 3. The structure of [Cr(ur) ][Co(Ox) ] 3.5H O (IV): crystallographically independent part
6
3
2
(а); and packing of complex cations and anions in the structure (projection perpendicular to а
axis) (b). The ellipsoids of thermal vibrations are plotted at a probability level of 50%. The
hydrogen bonds are presented as dotted lines.
1
3

ACCEPTED MANUSCRIPT
a
b
c
d
Figure 4. Thermal analysis of I and II. TG and DSC curves of I and II: a) in air; c) in argon. IR
analysis of GPT for I: b) in air; d) in nitrogen.
1
4

ACCEPTED MANUSCRIPT
a
b
c
d
Figure 5. Thermal analysis of III and IV. TG and DSC curves of III and IV: a) in air; c) in
argon. IR analysis of GPT for III: b) in air; d) in nitrogen.
1
5

ACCEPTED MANUSCRIPT
III
III
–
The compounds [Cr(CO(NH ) ) ][ML ] (M = Fe (I, III), Co (II, IV); L = CN (I, II),
2
2 6
6
2–
1
/2C O (III, IV) have been synthesized.
2 4
Their structures and thermal behavior have been studied. I, II, IV are triclinic, III is
orthorhombic one.
The end solid products are spinels of type MCr O , gaseous products are HCN, NH , HNCO,
2
4
3
N O, CO, CO , CO(NH ) .
2
2
2 2