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Nuclear quadrupole resonance of chlorine in sodium tetrachloroiodate(III) dihydrate
KKJRNAL
OF MAGNETIC
RESONANCE
8,179-l
82 (1972)
NucliearQuadrupoleResonanceof Chlorine in Sodium Tetrachloroiodate(IH) Dihydrate AKINOBU
SASANE,” DAIYU
NAKAMURA,
AND MASAJI KUBO
Department of Chemistry, Nagoya University, Chikusa, Nagoya, Japan Received December 28, 1971 The nuclear quadrupole resonance of chlorine in sodium tetrachloroiodate(II1) dihydrate was observed between 77 and 365°K. Four resonance lines were observed indicating the presence of four kinds of crystalIographically nonequivalent chlorine atoms in the crystals. Unlike other resonance lines, the lowest-frequency line shows a positive temperature coefficient of resonance frequency. X-Ray powder patterns indicate the isomorphism of this complex with sodium tetrachloroaurate(II1) dihydrate. With the aid of X-ray crystal analysis of the latter compound, it is concluded that the resonance line showing the positive temperature coefficient is attributable to chlorine atoms involved in hydrogen bonding. INTRODUCTION
We have studied the pure quadrupole resonance of halogens in various tetrahaloaurates(III), and found that the lowest-frequency resonance line of a quartet observed for sodium tetrachloroaurate(II1) dihydrate and tetrabromoaurate(II1) dihydrate shows a positive temperature coefficient (I, 2). This anomaly could be interpreted with the aid of X-ray crystal analysis as having its origin in hydrogen bond formation involving halogen atoms. For sodium tetrachloroaurate(II1) dihydrate, Fryer and Smith also investigated the pure quadrupole resonance of chlorine and reached a similar conclusion (3). The crystal structure of sodium tetrachloroiodate(II1) dihydrate has not yet been etermined, but tetrachloroiodate(II1) ions have been known to have a square configuration in potassium tetrachloroiodate(II1) (4) as do tetrachloroaurate(II1) ions in sodium tetrachloroaurate(II1) dihydrate. Cornwell and Yamasaki reported that sodium tetrachloroiodate(II1) dihydrate yielded four NQR frequencies at room, dryice, and liquid-nitrogen temperatures (5). The data tabulated in their paper indicate that the lowest-frequency line shows a positive temperature coefficient unless some phase transitions take place. However, the authors failed to discuss the temperature dependence of resonance frequencies. Therefore, we have investigated the temperature dependence of quadrupole resonance frequencies in order to discuss the temperature coefficient in relation to hydrogen bonds. EXPERIMENTAL
SECTION
A modified Dean-type superregenerative spectrometer (6) was employed for the determination of quadrupole resonance frequencies in a temperature range between 77 * Present address: Faculty of Science, Shinshu University, Matsumoto, Japan. 0 1972 by Academic Press, Inc. 179 of reproduction in any form reserved.
Copyright All rights
8
180
SASANE,
NAKAMURA,
AND
KUBO
and 365°K. Resonance frequencies were measured by means of a Model JR-5178 frequency counter from Takeda Riken Company. The temperature was determined by means of a chromel-alumel thermocouple calibrated at standard temperatures” The observed temperatures were accurate within &l”K. The sample was prepared in accordance with the method described in the literature (5). RESULTS
Table 1 gives the resonance frequencies at room, dry-ice, and liquid-nitrogen temperatures. At liquid-nitrogen temperature, the highest and the second highest resonance frequencies are slightly higher (ea. 100 and 50 kWz, respectively) than those reported by Cornwell and Yamasaki (5). Other frequencies listed in Table 1 agree very well with those reported by the authors. TABLE
1
FREQUENCIESOF~YZIINSODIUM TETRACHLOROIODATE(III)DIHYDRATE
NQR
Multiplet component
Frequency 77°K
(MHz) 193°K
I
20.008 22.653 23.305 23.925
20.259” 22.411 23.117 23.643
a Errors
are estimated
II III IV
to be less than
(,tO.OOl) 293°K 20.574” 22.184 22.896 23.281 hO.002.
At low temperature, the four resonance lines were fairly broad, the lowest-frequency line being broader than other multiplet components. With increasing temperature, they became sharper. Above room temperature, the quartet lines were fairly sharp and their intensity decreased with increasing temperature until they disappeared in the noise level at about 361°K. DISCUSSION
Figure 1 shows the temperature dependence of quadrupole resonance frequencies The curves are smooth indicating that no phase transitions take place in the temperature range investigated. A marked feature of the temperature dependence is that the lowestfrequency line of the quartet shows a positive temperature coefficient, whereas other lines have normal negative temperature coefficients in the whole range of temperature investigated. Moreover, the resonance frequency of the lowest-frequency line is much lower than those of other lines especially at liquid-nitrogen temperature. The characteristic resonance pattern bears a strong resemblance to that of sodium tetrachloroaurate(II1) dihydrate already reported (2). This suggests that the complex is isomorphous with sodium tetrachIoroaurate(II1) dihydrate. Fortunately, the X-ray crystal analysis of the latter compound has been performed by Bonamico ef al. (7). Therefore, we have taken the X-ray powder patterns of the two complexes in order to
NQR
OF cl
IN SODIUM
181
TETRACHLOROIODATE
check the isomorphism by use of a Model D-3F X-ray diffractometer from Rigaku Denki Company equipped with a copper anticathode. A goniometer was calibrated with a standard sample of silicon. The patterns obtained closely resembled those of sodium tetrachloroaurate(II1) dihydrate regarding the angle of diffraction and the intensity of lines, the one-to-one correspondence of diffraction lines being complete *-. . . . . . . . .
. . * * * . . . ..*. .. . . . * -. .... ..
. .. . . . . . . . . 23 1. . . . . . . . .
4,,1 I
* ** --* - . .. . ~. . . . . . . . .
-*a .I”. . ...* *--. ** . .
* *-...... III -***--*
*-*****.
..-.........,.
- * -* . . . .II.. ....*
r
*.. .
**.*
-**a..
. .. . . .
* *....
..****
I
NalCl,Si,O
%I
I I, t
*..... . . . . . . ,. . 100
*.*........
..*
-‘*
--
. .
I . . .* . . ..-
*I*I 200
/
1 SOP
Temp., ‘1
FIG. 1. Temperature dihydrate.
dependence
of the NQR
frequencies
of sodium
tetrachloroiodate(IIT)
between the two complexes. This indicates that the compound in question is isostructural with NaAuCI,*2H,O and forms orthorhombic crystals belonging to the space group Pnnza (7). For the purpose of determining lattice constants, nonoverlapping lines were chosen below 28 = 40”, and the Miller indices of diffraction lines were TABLE
2
COMPARISONOF CALCULATED VALUESWITH~BSERVED~NESFOR SODIUMTETRACHLOROIODATE(III) DIHYDRATE
hkl 101 200 111 210 002 202 020 121 220 213 412
sin2 eobsd 0.01016 1281 2185 2447 2816 4098 4651 5649 5941 8759 9158
sin20
sin* ecalcd 0.01025 1291 2185 2460 2800 4101 4637 5663 5939 8761 9162
182
SASANE,
NAKAMURA,
AND
KUBO
determined with the aid of the diffraction patterns of sodium tetrachlor~aurate~~r~) dihydrate. The lattice constants evaluated are a = 13.51 A 0.06, b = 7.15 i 0.03: and c = 9.21 F 0.04 A. The diffraction data are given in Table 2. Because of the isomorphous relationship as confirmed above, it is highly likely that one of the four chlorine atoms in an ICI, ion is involved in weak hydrogen bonds with four water molecules as in the crystals of sodium tetrachloroaurate(II1) dihydrate (2) and is responsible for the positive temperature coefficient of a quadrupole resonance frequency. The infrared spectroscopy of water molecules in sodium tetrachloroiodate(II1) dihydrate also lends support to the existence of weak 0-H. * Cl hydrogen bonds in the crystals (8). REFERENCES SASANE, T. MATUO, D. NAKAMLJRA, AND M. Kmo, Bull. Chem. Sot. Jap. 43,1908 (1970). SASANE, T. MATUO, D. NAKAMLJRA, AND M. KUBO, J. Magn. Resonnnce 4,257 (197!j. W. FRYER AND J. A. S. SMITH, J. Chem. Sot. A 1029 (1970). C. L. MOONEY, Z. Krist. 98, 377 (1938). D. CORNWELL AND R. S. YAMASAKI, J. Chem. Phys. 27,106O (1957). SASANE, D. NAKAMKJRA, AND M. Kmo, J. Mugn. Resonance ~$76 (1970). BONAMICO, G. DESSY, AND A. VACIAGO, Atti Accad. Naz. Lincei, Cl. Sci. Fis. Mat. Natw. 39, 504 (1965). 8. K. ICHIDA, Y. KURODA, D. NAKAMURA, AND M. Kmo, Bull. Chem. Sot. Jap. 44, 1996 (1971).
1. 2. 3. 4. 5. 6. 7.
A. A. C. R. C. A. M.
Rend.
OF MAGNETIC
RESONANCE
8,179-l
82 (1972)
NucliearQuadrupoleResonanceof Chlorine in Sodium Tetrachloroiodate(IH) Dihydrate AKINOBU
SASANE,” DAIYU
NAKAMURA,
AND MASAJI KUBO
Department of Chemistry, Nagoya University, Chikusa, Nagoya, Japan Received December 28, 1971 The nuclear quadrupole resonance of chlorine in sodium tetrachloroiodate(II1) dihydrate was observed between 77 and 365°K. Four resonance lines were observed indicating the presence of four kinds of crystalIographically nonequivalent chlorine atoms in the crystals. Unlike other resonance lines, the lowest-frequency line shows a positive temperature coefficient of resonance frequency. X-Ray powder patterns indicate the isomorphism of this complex with sodium tetrachloroaurate(II1) dihydrate. With the aid of X-ray crystal analysis of the latter compound, it is concluded that the resonance line showing the positive temperature coefficient is attributable to chlorine atoms involved in hydrogen bonding. INTRODUCTION
We have studied the pure quadrupole resonance of halogens in various tetrahaloaurates(III), and found that the lowest-frequency resonance line of a quartet observed for sodium tetrachloroaurate(II1) dihydrate and tetrabromoaurate(II1) dihydrate shows a positive temperature coefficient (I, 2). This anomaly could be interpreted with the aid of X-ray crystal analysis as having its origin in hydrogen bond formation involving halogen atoms. For sodium tetrachloroaurate(II1) dihydrate, Fryer and Smith also investigated the pure quadrupole resonance of chlorine and reached a similar conclusion (3). The crystal structure of sodium tetrachloroiodate(II1) dihydrate has not yet been etermined, but tetrachloroiodate(II1) ions have been known to have a square configuration in potassium tetrachloroiodate(II1) (4) as do tetrachloroaurate(II1) ions in sodium tetrachloroaurate(II1) dihydrate. Cornwell and Yamasaki reported that sodium tetrachloroiodate(II1) dihydrate yielded four NQR frequencies at room, dryice, and liquid-nitrogen temperatures (5). The data tabulated in their paper indicate that the lowest-frequency line shows a positive temperature coefficient unless some phase transitions take place. However, the authors failed to discuss the temperature dependence of resonance frequencies. Therefore, we have investigated the temperature dependence of quadrupole resonance frequencies in order to discuss the temperature coefficient in relation to hydrogen bonds. EXPERIMENTAL
SECTION
A modified Dean-type superregenerative spectrometer (6) was employed for the determination of quadrupole resonance frequencies in a temperature range between 77 * Present address: Faculty of Science, Shinshu University, Matsumoto, Japan. 0 1972 by Academic Press, Inc. 179 of reproduction in any form reserved.
Copyright All rights
8
180
SASANE,
NAKAMURA,
AND
KUBO
and 365°K. Resonance frequencies were measured by means of a Model JR-5178 frequency counter from Takeda Riken Company. The temperature was determined by means of a chromel-alumel thermocouple calibrated at standard temperatures” The observed temperatures were accurate within &l”K. The sample was prepared in accordance with the method described in the literature (5). RESULTS
Table 1 gives the resonance frequencies at room, dry-ice, and liquid-nitrogen temperatures. At liquid-nitrogen temperature, the highest and the second highest resonance frequencies are slightly higher (ea. 100 and 50 kWz, respectively) than those reported by Cornwell and Yamasaki (5). Other frequencies listed in Table 1 agree very well with those reported by the authors. TABLE
1
FREQUENCIESOF~YZIINSODIUM TETRACHLOROIODATE(III)DIHYDRATE
NQR
Multiplet component
Frequency 77°K
(MHz) 193°K
I
20.008 22.653 23.305 23.925
20.259” 22.411 23.117 23.643
a Errors
are estimated
II III IV
to be less than
(,tO.OOl) 293°K 20.574” 22.184 22.896 23.281 hO.002.
At low temperature, the four resonance lines were fairly broad, the lowest-frequency line being broader than other multiplet components. With increasing temperature, they became sharper. Above room temperature, the quartet lines were fairly sharp and their intensity decreased with increasing temperature until they disappeared in the noise level at about 361°K. DISCUSSION
Figure 1 shows the temperature dependence of quadrupole resonance frequencies The curves are smooth indicating that no phase transitions take place in the temperature range investigated. A marked feature of the temperature dependence is that the lowestfrequency line of the quartet shows a positive temperature coefficient, whereas other lines have normal negative temperature coefficients in the whole range of temperature investigated. Moreover, the resonance frequency of the lowest-frequency line is much lower than those of other lines especially at liquid-nitrogen temperature. The characteristic resonance pattern bears a strong resemblance to that of sodium tetrachloroaurate(II1) dihydrate already reported (2). This suggests that the complex is isomorphous with sodium tetrachIoroaurate(II1) dihydrate. Fortunately, the X-ray crystal analysis of the latter compound has been performed by Bonamico ef al. (7). Therefore, we have taken the X-ray powder patterns of the two complexes in order to
NQR
OF cl
IN SODIUM
181
TETRACHLOROIODATE
check the isomorphism by use of a Model D-3F X-ray diffractometer from Rigaku Denki Company equipped with a copper anticathode. A goniometer was calibrated with a standard sample of silicon. The patterns obtained closely resembled those of sodium tetrachloroaurate(II1) dihydrate regarding the angle of diffraction and the intensity of lines, the one-to-one correspondence of diffraction lines being complete *-. . . . . . . . .
. . * * * . . . ..*. .. . . . * -. .... ..
. .. . . . . . . . . 23 1. . . . . . . . .
4,,1 I
* ** --* - . .. . ~. . . . . . . . .
-*a .I”. . ...* *--. ** . .
* *-...... III -***--*
*-*****.
..-.........,.
- * -* . . . .II.. ....*
r
*.. .
**.*
-**a..
. .. . . .
* *....
..****
I
NalCl,Si,O
%I
I I, t
*..... . . . . . . ,. . 100
*.*........
..*
-‘*
--
. .
I . . .* . . ..-
*I*I 200
/
1 SOP
Temp., ‘1
FIG. 1. Temperature dihydrate.
dependence
of the NQR
frequencies
of sodium
tetrachloroiodate(IIT)
between the two complexes. This indicates that the compound in question is isostructural with NaAuCI,*2H,O and forms orthorhombic crystals belonging to the space group Pnnza (7). For the purpose of determining lattice constants, nonoverlapping lines were chosen below 28 = 40”, and the Miller indices of diffraction lines were TABLE
2
COMPARISONOF CALCULATED VALUESWITH~BSERVED~NESFOR SODIUMTETRACHLOROIODATE(III) DIHYDRATE
hkl 101 200 111 210 002 202 020 121 220 213 412
sin2 eobsd 0.01016 1281 2185 2447 2816 4098 4651 5649 5941 8759 9158
sin20
sin* ecalcd 0.01025 1291 2185 2460 2800 4101 4637 5663 5939 8761 9162
182
SASANE,
NAKAMURA,
AND
KUBO
determined with the aid of the diffraction patterns of sodium tetrachlor~aurate~~r~) dihydrate. The lattice constants evaluated are a = 13.51 A 0.06, b = 7.15 i 0.03: and c = 9.21 F 0.04 A. The diffraction data are given in Table 2. Because of the isomorphous relationship as confirmed above, it is highly likely that one of the four chlorine atoms in an ICI, ion is involved in weak hydrogen bonds with four water molecules as in the crystals of sodium tetrachloroaurate(II1) dihydrate (2) and is responsible for the positive temperature coefficient of a quadrupole resonance frequency. The infrared spectroscopy of water molecules in sodium tetrachloroiodate(II1) dihydrate also lends support to the existence of weak 0-H. * Cl hydrogen bonds in the crystals (8). REFERENCES SASANE, T. MATUO, D. NAKAMLJRA, AND M. Kmo, Bull. Chem. Sot. Jap. 43,1908 (1970). SASANE, T. MATUO, D. NAKAMLJRA, AND M. KUBO, J. Magn. Resonnnce 4,257 (197!j. W. FRYER AND J. A. S. SMITH, J. Chem. Sot. A 1029 (1970). C. L. MOONEY, Z. Krist. 98, 377 (1938). D. CORNWELL AND R. S. YAMASAKI, J. Chem. Phys. 27,106O (1957). SASANE, D. NAKAMKJRA, AND M. Kmo, J. Mugn. Resonance ~$76 (1970). BONAMICO, G. DESSY, AND A. VACIAGO, Atti Accad. Naz. Lincei, Cl. Sci. Fis. Mat. Natw. 39, 504 (1965). 8. K. ICHIDA, Y. KURODA, D. NAKAMURA, AND M. Kmo, Bull. Chem. Sot. Jap. 44, 1996 (1971).
1. 2. 3. 4. 5. 6. 7.
A. A. C. R. C. A. M.
Rend.