1,1,3,3-Tetramethylguanidinium dihydrogenorthophosphate

TLDR: In the title compound, C5H14N3+·H2PO4−, the cation has a central guanidinium fragment with a planar geometry, as expected for a central Csp2 atom with a small charge delocalization along the three C—N bonds.

Abstract: In the title compound, C5H14N3+·H2PO4−, the cation has a central guanidinium fragment with a planar geometry, as expected for a central Csp2 atom with a small charge delocalization along the three C—N bonds. The crystal packing is governed by hydrogen bonds so that the phosphate anions are linked head to tail, forming chains running parallel to the c direction. These chains in turn are interconnected by hydrogen bonds to intermediate tetra­methyl­guanidinium cations forming hydrogen-bonded molecular layers stacked parallel to the bc crystal planes.

Figures

Table 1 Selected geometric parameters (AÊ , ).

Full text

organic compounds
888 # 2000 International Union of Crystallography

Printed in Great Britain ± all rights reserved Acta Cryst. (2000). C56, 888±889
1,1,3,3-Tetramethylguanidinium
dihydrogenorthophosphate
A. Criado,
a
* M. J. Dia
Â
nez,
a
S. Pe
Â
rez-Garrido,
a
I. M. L.
Fernandes,
b
M. Belsley
b
and E. de Matos Gomes
b
a
Instituto de Ciencia de Materiales de Sevilla, Departamento de Fõ
Â
sica de la Materia
Condensada, CSIC ± Universidad de Sevilla, Apartado 1065, 41080 Sevilla, Spain,
and
b
Departamento de Fõ
Â
sica, Universidade do Minho, 4709 Braga, Portugal
Correspondence e-mail: criado@cica.es
Received 2 March 2000
Accepted 5 April 2000
In the title compound, C
5
H
14
N
3
+
H
2
PO
4
ÿ
, the cation has a
central guanidinium fragment with a planar geometry, as
expected for a central Csp
2
atom with a small charge
delocalization along the three CÐN bonds. The crystal
packing is governed by hydrogen bonds so that the phosphate
anions are linked head to tail, forming chains running parallel
to the c direction. These chains in turn are interconnected by
hydrogen bonds to intermediate tetramethylguanidinium
cations forming hydrogen-bonded molecular layers stacked
parallel to the bc crystal planes.
Comment
Inorganic salts of phosphoric acids form compounds that
exhibit a wealth of interesting physical properties such as
ferroelectricity and non-linear optical phenomena like second
harmonic generation; a classical example is potassium di-
hydrogen orthophosphate (KDP) (Rafhkovich, 1991). A
general synthetic route to obtain organo-dihydrogen ortho-
phosphate crystals has been detailed (Masse & Zyss, 1991). In
all these compounds, there is an inorganic subnetwork formed
by the dihydrogen orthophosphate anions (H
2
PO
4
)
n
. When
the organic species are strongly dipolar, the anion sublattice is
organized in a polar structure; examples are l-argininium di-
hydrogen orthophosphate monohydrate (Aoki et al., 1971), 2-
amino-5-nitropyridinium dihydrogen orthophosphate (Kotler
et al., 1992) and sarcosine dihydrogen orthophosphate
(Averbuch-Pouchot et al., 1988). In the case of a weakly
dipolar organic species such as glycine, the anion sublattice
will organize in a nonpolar structure (Averbuch-Pouchot et al.,
1988). As part of a project to study new compounds with
potentially interesting optical and dielectric properties, we
have synthesized the title compound, (I). Similar to amino-
guanidinium dihydrogen orthophosphate (Adams, 1977), we
report here its crystal structure, as determined by single-
crystal X-ray diffraction.
The compound crystallizes in a centrosymmetric space
group; consequently, no non-linear optical effects are
observed. Differential scanning calorimetry measurements
performed from 93 to 673 K did not show any phase transition.
The melting point occurs at about 493 K, followed by
decomposition.
The geometry of the guanidinium group in (I) is planar, as
expected for sp
2
hybridization of the central C atom (Fig. 1).
The  delocalization along the three CÐN bonds gives rise to
C1ÐN2 [1.344 (1) A
Ê
] and C1ÐN3 [1.346 (1) A
Ê
] bond lengths
larger than the value expected for a Csp
2
N bond (1.295 A
Ê
)
and close to the expected value for a delocalized C
N double
bond [1.339 (5) A
Ê
]. The C1ÐN1 bond length [1.320 (1) A
Ê
]is
somewhat shorter and compares well with the average value
for the guanidinium cation (1.321 A
Ê
) (Allen et al., 1987). The
larger value for the C1ÐN2 and C1ÐN3 bond lengths must be
ascribed to the methyl substitution which makes the three
bonds non-equivalent. Indeed, simple molecular-orbital
semiempirical calculations (extended Hu
È
ckel) give different
atomic charges on N1 (ÿ0.376 e) and N2 and N3 (ÿ0.590 e).
As may be expected, the two PÐO distances for the OH
groups are signi®cantly longer than the other two PÐO
distances.
The basis of the molecular engineering interest in these salts
is the obtention of structures with potential physical properties
as a result of the hydrogen-bond crystal network, which tends
to reinforce the properties exhibited by the isolated molecule
by arranging them as linear or layered molecular patterns.
In our case the hydrogen bonds also give rise to an inter-
esting arrangement, which is best understood with the aid of
the diagram corresponding to the crystal structure viewed
perpendicular to the ab plane (Fig. 2). On one hand, each
phosphate ion is connected by two hydrogen bonds to each
phosphate ion related to it by a c glide plane with both positive
and negative fractional c translations. Given that the central P
atoms lie at a very close distance to the glide planes (0.32 A
Ê
), it
results in approximately linear phosphate chains parallel to
the c direction. On the other hand, each tetramethyl-
guanidinium ion is hydrogen-bonded to two phosphate ions
related to each other by an inversion centre and belonging to
different chains, giving rise to a framework of molecules
Acta Crystallographica Section C
Crystal Structure
Communications
ISSN 0108-2701
Figure 1
Structure of (I) showing 30% probability displacement ellipsoids.

connected by hydrogen bonds in the form of layers parallel to
the bc crystal planes and stacked according to the a lattice
translation period. Besides the above, two CÐHO contacts
interrelating molecules within the same layer and not depicted
in the diagram have been detected.
Experimental
The title compound was prepared by mixing equimolar portions of
two reagents: 1,1,3,3-tetramethylguanidine (99%) and phosphoric
acid (85%) in a 1:1 solution of ethanol and water at room tempera-
ture. Good quality, colourless single crystals of prism habit were
grown from the solution by slow evaporation, one of which was
selected and used for the X-ray analysis.
Crystal data
C
5
H
14
N
3
+
H
2
PO
4
ÿ
M
r
= 213.18
Monoclinic, P2
1
=c
a = 11.225 (3) A
Ê
b = 10.951 (1) A
Ê
c = 8.430 (2) A
Ê
 = 103.50 (1)

V = 1007.6 (4) A
Ê
3
Z =4
D
x
= 1.405 Mg m
ÿ3
D
m
= 1.40 Mg m
ÿ3
D
m
measured by ¯otation in
bromobenzene and acetone
Mo K radiation
Cell parameters from 25
re¯ections
 = 7±12

 = 0.264 mm
ÿ1
T = 293 (2) K
Prism, colourless
0.80  0.50  0.40 mm
Data collection
Enraf±Nonius CAD-4 diffract-
ometer
!±2 scans
3777 measured re¯ections
3777 independent re¯ections
3257 re¯ections with I >2(I)

max
= 32.96

h =0! 17
k =0! 16
l = ÿ12 ! 12
3 standard re¯ections
frequency: 60 min
intensity decay: none
Re®nement
Re®nement on F
2
R[F
2
>2(F
2
)] = 0.034
wR(F
2
) = 0.105
S = 1.080
3777 re¯ections
124 parameters
H-atom parameters constrained
w = 1/[
2
(F
o
2
) + (0.0639P)
2
+ 0.1114P]
where P =(F
o
2
+2F
c
2
)/3
(/)
max
< 0.001

max
= 0.46 e A
Ê
ÿ3

min
= ÿ0.37 e A
Ê
ÿ3
Data collection and cell re®nement: CAD-4 Software (Enraf±
Nonius, 1989); data reduction: XRAY76 (Stewart et al., 1976);
program(s) used to solve structure: SIR92 (Altomare et al., 1994);
program(s) used to re®ne structure: SHELXL93 (Sheldrick, 1993);
molecular graphics: PLATON (Spek, 1994); software used to prepare
material for publication: PARST (Nardelli, 1995) and PARSTCIF
(Nardelli, 1991).
This work was supported by the Spanish CICYT project
PB98-1126. We also acknowledge travel support from Accion
Integrada Hispano-Portuguesa HP 1999-0070.
Supplementary data for this paper are available from the IUCr electronic
archives (Reference: NA1466). Services for accessing these data are
described at the back of the journal.
References
Adams, J. M. (1977). Acta Cryst. B33, 1513±1515.
Allen, F. H., Kennard, O., Watson, D. G., Brammer, L., Orpen, A. G. & Taylor,
R. (1987). J. Chem. Soc. Perkin Trans. 2, pp. S1±19.
Altomare, A., Cascarano, G., Giacovazzo, C., Guagliardi, A., Burla, M. C.,
Polidori, G. & Camalli, M. (1994). J. Appl. Cryst. 27, 435.
Aoki, K., Nagano, K. & Iitaka, Y. (1971). Acta Cryst. B27, 11±23.
Averbuch-Pouchot, A. T., Durif, A. & Guitel, J. C. (1988). Acta Cryst. C44, 99±
102.
Enraf±Nonius (1989). CAD-4 Software. Version 5.0. Enraf±Nonius, Delft, The
Netherlands.
Kotler, Z., Hierle, R., Josse, D., Zyss, J. & Masse, R. (1992). J. Opt. Soc. Am.
B9, 534±547.
Masse, R. & Zyss, J. (1991). Mol. Eng. 1, 141±152.
Nardelli, M. (1991). PARSTCIF. University of Parma, Italy.
Nardelli, M. (1995). J. Appl. Cryst. 28, 659.
Rafhkovich, L. N. (1991). KDP-Family Single Crystals. Bristol: IOP Publishing.
Sheldrick, G. M. (1993). SHELXL93. University of Go
È
ttingen, Germany.
Spek, A. L. (1994). PLATON. University of Utrecht, The Netherlands.
Stewart, J. M., Machin, P. A., Dickinson, C. W., Ammon, H. L., Heck, H. &
Flack, H. (1976). The XRAY76 System. Technical Report TR-446.
Computer Science Center, University of Maryland, USA.
Acta Cryst. (2000). C56, 888±889 A. Criado et al.

C
5
H
14
N
3
+
H
2
PO
4
ÿ
 889
organic compounds
Table 1
Selected geometric parameters (A
Ê
,

).
P1ÐO4 1.4968 (7)
P1ÐO3 1.5148 (7)
P1ÐO1 1.5629 (8)
P1ÐO2 1.5800 (8)
N1ÐC1 1.3198 (13)
N3ÐC1 1.3451 (14)
N3ÐC5 1.461 (2)
N3ÐC4 1.458 (2)
N2ÐC1 1.3447 (15)
N2ÐC3 1.466 (2)
N2ÐC2 1.455 (2)
O4ÐP1ÐO3 114.78 (5)
O4ÐP1ÐO1 108.64 (5)
O3ÐP1ÐO1 109.11 (4)
O4ÐP1ÐO2 110.24 (4)
O3ÐP1ÐO2 108.20 (5)
O1ÐP1ÐO2 105.47 (5)
C1ÐN3ÐC5 120.91 (10)
C1ÐN3ÐC4 121.53 (12)
C5ÐN3ÐC4 114.50 (12)
C1ÐN2ÐC3 121.02 (12)
C1ÐN2ÐC2 121.27 (11)
C3ÐN2ÐC2 115.34 (12)
N1ÐC1ÐN2 120.78 (11)
N1ÐC1ÐN3 120.22 (10)
N2ÐC1ÐN3 119.01 (10)
Table 2
Hydrogen-bonding geometry (A
Ê
,

).
DÐHADÐH HADADÐHA
N1ÐH1AO3 0.88 2.08 2.924 (1) 161
O2ÐH2O3
i
0.84 1.79 2.616 (1) 167
O1ÐH1O4
ii
0.84 1.71 2.541 (1) 169
N1ÐH1BO3
iii
0.88 2.07 2.894 (1) 155
C5ÐH5BO2
iii
0.98 2.56 3.521 (2) 167
C5ÐH5AO2
iv
0.98 2.67 3.607 (2) 159
Symmetry codes: (i) x; ÿ
1
2
ÿ y; z ÿ
1
2
; (ii) x; ÿ
1
2
ÿ y;
1
2
 z; (iii) ÿx; ÿy; 1 ÿ z; (iv)
x; 1  y; z.
Figure 2
The molecular packing viewed along an axis perpendicular to the ab
plane showing the hydrogen bonding.

supporting information
sup-1
Acta Cryst. (2000). C56, 888-889
supporting information
Acta Cryst. (2000). C56, 888-889 [doi:10.1107/S0108270100005187]
1,1,3,3-Tetramethylguanidinium dihydrogenorthophosphate
A. Criado, M. J. Diánez, S. Pérez-Garrido, I. M. L. Fernandes, M. Belsley and E. de Matos
Gomes
Computing details
Data collection: CAD-4 Software (Enraf-Nonius, 1989); cell refinement: SET4 (de Boer & Duissenberg, 1984) and
CELDIM (CAD4, Retting, 1989); data reduction: XRAY76 System (Stewart et al., 1976); program(s) used to solve
structure: SIR92 (Altomare et al., 1994); program(s) used to refine structure: SHELXL93 (Sheldrick, 1993); molecular
graphics: PLATON (Spek, 1994); software used to prepare material for publication: PARST (Nardelli, 1995) and
PARSTCIF (Nardelli, 1991).
1,1,3,3-tetramethyl guanidinium phosphate
Crystal data
C
5
H
14
N
3
+
·H
2
PO
4
−
M
r
= 213.18
Monoclinic, P2
1
/c
a = 11.225 (3) Å
b = 10.951 (1) Å
c = 8.430 (2) Å
β = 103.50 (1)°
V = 1007.6 (4) Å
3
Z = 4
F(000) = 456
D
x
= 1.405 Mg m
−3
D
m
= 1.40 Mg m
−3
D
m
measured by flotation in bromobenzene and
acetone
Melting point: 493 K
Mo Kα radiation, λ = 0.71069 Å
Cell parameters from 25 reflections
θ = 7–12°
µ = 0.26 mm
−1
T = 293 K
Prism, colourless
0.80 × 0.50 × 0.40 mm
Data collection
Enraf-Nonius CAD4
diffractometer
Radiation source: fine-focus sealed tube
Graphite monochromator
ω–2θ scans
3777 measured reflections
3777 independent reflections
3257 reflections with I > 2σ(I)
R
int
= 0.000
θ
max
= 33.0°, θ
min
= 2.6°
h = 0→17
k = 0→16
l = −12→12
3 standard reflections every 60 min min
intensity decay: none
Refinement
Refinement on F
2
Least-squares matrix: full
R[F
2
> 2σ(F
2
)] = 0.034
wR(F
2
) = 0.105
S = 1.08
3777 reflections
124 parameters
0 restraints
Primary atom site location: structure-invariant
direct methods
Secondary atom site location: difference Fourier
map

supporting information
sup-2
Acta Cryst. (2000). C56, 888-889
Hydrogen site location: inferred from
neighbouring sites
H-atom parameters constrained
Calculated w = 1/[σ
2
(F
o
2
) + (0.0639P)
2
+
0.1114P]
where P = (F
o
2
+ 2F
c
2
)/3
(Δ/σ)
max
< 0.001
Δρ
max
= 0.46 e Å
−3
Δρ
min
= −0.37 e Å
−3
Special details
Geometry. All e.s.d.'s (except the e.s.d. in the dihedral angle between two l.s. planes) are estimated using the full
covariance matrix. The cell e.s.d.'s are taken into account individually in the estimation of e.s.d.'s in distances, angles and
torsion angles; correlations between e.s.d.'s in cell parameters are only used when they are defined by crystal symmetry.
An approximate (isotropic) treatment of cell e.s.d.'s is used for estimating e.s.d.'s involving l.s. planes.
Refinement. Refinement on F
2
for ALL reflections except for 0 with very negative F
2
or flagged by the user for potential
systematic errors. Weighted R-factors wR and all goodnesses of fit S are based on F
2
, conventional R-factors R are based
on F, with F set to zero for negative F
2
. The observed criterion of F
2
> σ(F
2
) is used only for calculating R_factor_obs
etc. and is not relevant to the choice of reflections for refinement. R-factors based on F
2
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 (Å
2
)
xyzU
iso
*/U
eq
P1 0.21200 (2) −0.22099 (2) 0.44607 (3) 0.02297 (8)
O4 0.26662 (8) −0.14310 (7) 0.33544 (9) 0.0318 (2)
O3 0.12944 (7) −0.15363 (7) 0.53532 (9) 0.0296 (2)
O2 0.13625 (9) −0.32927 (8) 0.34687 (10) 0.0384 (2)
H2 0.1421 −0.3263 0.2494 0.058*
O1 0.31819 (7) −0.28321 (8) 0.57362 (10) 0.0348 (2)
H1 0.2919 −0.3067 0.6540 0.052*
N1 0.13166 (8) 0.11300 (8) 0.51765 (13) 0.0358 (2)
H1A 0.14840 0.03517 0.53720 0.043*
H1B 0.05591 0.13620 0.47485 0.043*
N3 0.19506 (10) 0.31397 (9) 0.52252 (13) 0.0386 (2)
N2 0.33639 (9) 0.16108 (10) 0.61799 (14) 0.0415 (2)
C1 0.22015 (10) 0.19494 (10) 0.55254 (13) 0.0309 (2)
C5 0.08049 (12) 0.35246 (12) 0.4126 (2) 0.0459 (3)
H5A 0.0924 0.4317 0.3645 0.069*
H5B 0.0166 0.3597 0.4739 0.069*
H5C 0.0556 0.2918 0.3257 0.069*
C2 0.36472 (13) 0.04187 (13) 0.6937 (2) 0.0530 (4)
H2A 0.4411 0.0469 0.7782 0.080*
H2B 0.3742 −0.0177 0.6108 0.080*
H2C 0.2979 0.0162 0.7430 0.080*
C4 0.2563 (2) 0.40878 (13) 0.6335 (2) 0.0626 (4)
H4A 0.1968 0.4485 0.6851 0.094*
H4B 0.2915 0.4695 0.5723 0.094*
H4C 0.3216 0.3721 0.7177 0.094*
C3 0.43961 (13) 0.2244 (2) 0.5750 (2) 0.0630 (5)
H3A 0.4925 0.1646 0.5386 0.094*
H3B 0.4867 0.2681 0.6707 0.094*
H3C 0.40852 0.2828 0.4870 0.094*

supporting information
sup-3
Acta Cryst. (2000). C56, 888-889
Atomic displacement parameters (Å
2
)
U
11
U
22
U
33
U
12
U
13
U
23
P1 0.02584 (12) 0.02308 (12) 0.02056 (11) 0.00027 (7) 0.00656 (8) 0.00083 (7)
O4 0.0431 (4) 0.0283 (3) 0.0264 (3) −0.0075 (3) 0.0125 (3) 0.0006 (3)
O3 0.0303 (3) 0.0317 (3) 0.0277 (3) 0.0081 (3) 0.0087 (3) 0.0015 (3)
O2 0.0539 (5) 0.0356 (4) 0.0279 (3) −0.0179 (4) 0.0137 (3) −0.0048 (3)
O1 0.0294 (3) 0.0464 (5) 0.0301 (3) 0.0121 (3) 0.0100 (3) 0.0092 (3)
N1 0.0266 (4) 0.0261 (4) 0.0535 (6) 0.0007 (3) 0.0072 (4) −0.0021 (4)
N3 0.0430 (5) 0.0271 (4) 0.0458 (5) −0.0043 (4) 0.0105 (4) −0.0041 (4)
N2 0.0282 (4) 0.0438 (5) 0.0496 (6) −0.0022 (4) 0.0032 (4) −0.0042 (4)
C1 0.0300 (4) 0.0297 (4) 0.0339 (5) −0.0012 (3) 0.0093 (4) −0.0058 (4)
C5 0.0426 (6) 0.0347 (6) 0.0626 (8) 0.0028 (5) 0.0168 (6) 0.0122 (5)
C2 0.0417 (6) 0.0429 (7) 0.0653 (9) 0.0081 (5) −0.0059 (6) −0.0054 (6)
C4 0.0952 (13) 0.0332 (6) 0.0558 (8) −0.0164 (7) 0.0105 (8) −0.0130 (6)
C3 0.0298 (6) 0.0859 (13) 0.0708 (10) −0.0132 (7) 0.0071 (6) 0.0034 (9)
Geometric parameters (Å, º)
P1—O4 1.4968 (7) N2—C2 1.455 (2)
P1—O3 1.5148 (7) C5—H5A 0.98
P1—O1 1.5629 (8) C5—H5B 0.98
P1—O2 1.5800 (8) C5—H5C 0.98
O2—H2 0.84 C2—H2A 0.98
O1—H1 0.84 C2—H2B 0.98
N1—C1 1.3198 (13) C2—H2C 0.98
N1—H1A 0.88 C4—H4A 0.98
N1—H1B 0.88 C4—H4B 0.98
N3—C1 1.3451 (14) C4—H4C 0.98
N3—C5 1.461 (2) C3—H3A 0.98
N3—C4 1.458 (2) C3—H3B 0.98
N2—C1 1.3447 (15) C3—H3C 0.98
N2—C3 1.466 (2)
O4—P1—O3 114.78 (5) H5A—C5—H5B 109.5
O4—P1—O1 108.64 (5) N3—C5—H5C 109.47
O3—P1—O1 109.11 (4) H5A—C5—H5C 109.5
O4—P1—O2 110.24 (4) H5B—C5—H5C 109.5
O3—P1—O2 108.20 (5) N2—C2—H2A 109.47
O1—P1—O2 105.47 (5) N2—C2—H2B 109.47
P1—O2—H2 109.47 H2A—C2—H2B 109.5
P1—O1—H1 109.47 N2—C2—H2C 109.47
C1—N1—H1A 120.00 H2A—C2—H2C 109.5
C1—N1—H1B 120.00 H2B—C2—H2C 109.5
H1A—N1—H1B 120.0 N3—C4—H4A 109.47
C1—N3—C5 120.91 (10) N3—C4—H4B 109.47
C1—N3—C4 121.53 (12) H4A—C4—H4B 109.5
C5—N3—C4 114.50 (12) N3—C4—H4C 109.47

Frequently asked questions

Q1. What are the contributions in this paper?

In this paper, a guanidinium fragment with a planar geometry has been constructed for the C5H14N3 + H2PO4 cation with a small charge delocalization along the three CÐN bonds. 

Q2. What is the criterion used for calculating e.s.d.'?

Weighted R-factors wR and all goodnesses of fit S are based on F2, conventional R-factors R are based on F, with F set to zero for negative F2. 

Q3. What is the name of the compound?

CommentInorganic salts of phosphoric acids form compounds that exhibit a wealth of interesting physical properties such as ferroelectricity and non-linear optical phenomena like second harmonic generation; a classical example is potassium dihydrogen orthophosphate (KDP) (Rafhkovich, 1991). 

Q4. What is the basis of the molecular engineering interest in these salts?

The basis of the molecular engineering interest in these salts is the obtention of structures with potential physical properties as a result of the hydrogen-bond crystal network, which tends to reinforce the properties exhibited by the isolated molecule by arranging them as linear or layered molecular patterns. 

Q5. what is the criterion for calculating e.s.d.'s?

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2)x y z Uiso*/UeqH3C 0.40852 0.2828 0.4870 0.094*sup-3Acta Cryst. (2000). 

Q6. what is the re ection of prisms?

Good quality, colourless single crystals of prism habit were grown from the solution by slow evaporation, one of which was selected and used for the X-ray analysis. 

Q7. what is the criterion used for calculating e.s.d.'?

The observed criterion of F2 > σ(F2) is used only for calculating R_factor_obs etc. and is not relevant to the choice of reflections for refinement. 

Q8. What is the re ection of a prism?

Hydrogen site location: inferred from neighbouring sites H-atom parameters constrainedCalculated w = 1/[σ2(Fo2) + (0.0639P)2 + 0.1114P] where P = (Fo2 + 2Fc2)/3 (Δ/σ)max < 0.001 Δρmax = 0.46 e Å−3 Δρmin = −0.37 e Å−3Special detailsGeometry. 

Q9. What is the re nement of a prism?

The cell e.s.d.'s are taken into account individually in the estimation of e.s.d.'s in distances, angles and torsion angles; correlations between e.s.d.'s in cell parameters are only used when they are defined by crystal symmetry. 

Q10. What is the atomic structure of the prism?

Dm measured by flotation in bromobenzene and acetone Melting point: 493 K Mo Kα radiation, λ = 0.71069 Å Cell parameters from 25 reflections θ = 7–12° µ = 0.26 mm−1 T = 293 K Prism, colourless 0.80 × 0.50 × 0.40 mmData collectionEnraf-Nonius CAD4 diffractometer Radiation source: fine-focus sealed tube Graphite monochromator ω–2θ scans 3777 measured reflections 3777 independent reflections 3257 reflections with The author> 2σ(I)Rint = 0.000 θmax = 33.0°, θmin = 2.6° h = 0→17 k = 0→16 l = −12→12 3 standard reflections every 60 min min intensity decay: noneRefinementRefinement on F2 Least-squares matrix: full R[F2 > 2σ(F2)] = 0.034 wR(F2) = 0.105 S = 1.08 3777 reflections124 parameters 0 restraints Primary atom site location: structure-invariantdirect methods Secondary atom site location: difference Fouriermapsup-2Acta Cryst. (2000). 

Q11. What is the a lattice translation period?

connected by hydrogen bonds in the form of layers parallel to the bc crystal planes and stacked according to the a lattice translation period. 

Q12. what is the re ection of a prism?

1,1,3,3-tetramethyl guanidinium phosphateCrystal dataC5H14N3+·H2PO4− Mr = 213.18 Monoclinic, P21/c a = 11.225 (3) Å b = 10.951 (1) Å c = 8.430 (2) Å β = 103.50 (1)° V = 1007.6 (4) Å3 Z = 4 F(000) = 456Dx = 1.405 Mg m−3 Dm = 1.40 Mg m−3 

Q13. what is the re ection of prism habit?

Crystal data C5H14N3 + H2PO4ÿ Mr = 213.18 Monoclinic, P21=c a = 11.225 (3) AÊ b = 10.951 (1) AÊ c = 8.430 (2) AÊ= 103.50 (1)V = 1007.6 (4) AÊ 3 Z = 4 Dx = 1.405 Mg m ÿ3 Dm = 1.40 Mg m ÿ3Dm measured by ¯otation in bromobenzene and acetone Mo K radiation Cell parameters from 25re¯ections = 7±12 = 0.264 mmÿ1T = 293 (2) K Prism, colourless 0.80 0.50 0.40 mmData collectionEnraf±Nonius CAD-4 diffractometer !±2 scans 3777 measured re¯ections 3777 independent re¯ections 3257 re¯ections with The author> 2 (I) max = 32.96h = 0! 17 k = 0!