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A vibrational spectroscopy study of lead sulfur nitride
Notes the peak temperatures increase, exception being the Ca 2. and Mg z+ ion doped samples. T h e present findings reveal that if the valency state and electronic configuration of impurity cations are same but the ionic radii are different (e.g. Mg 2÷, Ca2*), the trend in the variation of E~ and A H values is similar, although there is a contrast in their behaviour when the absolute values of E a and A H are considered. It is also observed that for Ca 2+ and Cd z+ ion impurity doped samples, the trend in the variation of A H values is different inspite of their similar ionic sizes and oxidation states. This difference in the behaviour may probably be attributed to their different electronic configurations and different mode of decomposition. In the case of lanthanide impurity doped samples, the Td, T~, A H and E~ values decrease regularly from n e o d y m i u m to h o l m i u m as the ionic radii decrease (for the same percentage of the impurity).
Acknowledgements--One of the authors ( C R M Rao) is thankful to U.G.C. (India) for providing the financial assistance and the H e a d Chemistry d e p a r t m e n t for the research facilities. Department of Chemistry University of Roorkee Roorkee-24762, India
C. R A M A M O H A N R A O P. N. M E H R O T R A
REFERENCES 1. G. F. Huttig and E. L e h m a n n , Z. Phys. Chem. B19, 420 (1932). 2. J. Robin, Bull. Soc. Chim. Ft. 1078 (1953).
137
3. Y. A. Ugai, Zh. Obshch. Khim. 24, 1315 (1954). 4. V. P. Kornienko, Ukr. Khim. Zh. 23, 1996 (1957). 5. P. E. Yanwich and P. D. Zavitsanos, J. Phys. Chem. 68, 457 (1964). 6. L. Erdey and F. Paulik, Magy. Tudom. A k a d Kern. Tudom. Osztal. Kozl. 5, 461 (1955). 7. K. Kawagaki, J. Chem. Soc. Japan 72, 1079 (1951). 8. J. L. Doremieux and A. Boulle, Compt. Rend. 250, 3184 (1960). 9. D. Dollimore, J. Dollimore, and D. Nicholson. in Reactivity of solids (Edited by J. H. de Boer et al.) Proc. 4th Int. Symposium on the Reactivity of Solids. Elsevier, A m s t e r d a m (1961). 10. R. Sh. Mikhail, N. M. Guindy and 1. T. All, J. Appl. Chem. Biol. Technol 2,4, 583 (1974). 1 l. G. V. Subba Rao, M. Natarajan and C. N. R. Rao, J. Am. Ceram. Soc. 51, 179 (1968). 12. C. R a m a M o h a n Rao and P. N. Mehrotra. Ind. J. Chem. 15A, 1016 (1977). 13. D. Dollimore and D. Nicholson, J. Chem. Soc. 908 (1964). 14. C. R a m a M o h a n Rao and P. N. Mehrotra, l"hermo Chim Acta (in press). 15. H. J. Borchardt and F. Daniels, J. Am. (?hem. Sot'. 79, 41 (1957). 16. D. M. Speros and R. L. wood house, J. Phys. Chem. 72, 2846 (1968). 17. H. E. Kissinger, Analyt. Chem. 29, 1702 (1957L 18. K. J. Rao and C.N.R. Rao, J. Materials Sci. 1, 238 (1966). 19. C. R a m a M o h a n R a o and P. N. Mehrotra. Can. J. Chem. 56, 32 (1978).
J. inorg, nucl. Chem. Vok 42. pp. 137-139 ~) Pergamon Press Ltd,, 1980. Printed in Great Britain
0022-1902/80/0101-0137/$(12.00/0
A vibrational spectroscopy study of lead sulfur nitride (Received 30 March 1979) The reaction of a n h y d r o u s metal chlorides with tetrasulfur tetranitride in m e t h a n o l or ethanol has yielded three different c o m p o u n d s containing sulfur nitrogen bidentate ligands. These square planar c o m p o u n d s include M(SaNzH)2, M(S2N2H)(SaN) and M(S3N)2, when M is Ni, Pd or Pt [1-3]. W e have recently reported a comparison of their IR and R a m a n spectra using normal coordinate analysis [4]. W e now report our results of a vibrational study of the lead sulfur nitride, Pb(S2N2) and its ammoniate, Pb(S2N2) • N H 3.
to 3 3 c m -~ as nujol mulls on a polyethylene plate. The c o m p o u n d s were also run on a B e c k m a n IR-12 IR spectrophotometer from 4000-300 cm -1 using the K B r pellet technique. In both cases the spectra were obtained at room temperature and in a cold cell adaptable for use with the low frequency spectrophotometer. The instruments were calibrated by running the spectra of water vapor and polystyrene.
NORMAL COORDINATE ANALYSIS EXPE~NTAL The c o m p o u n d P b ( S 2 N z ) - N H 3 was prepared by the reaction of Pb(NO3) 2 with S 4 N 4 a t - 7 8 ° C in liquid amm o n i a [5, 6]. T h e olive green precipitate was washed with liquid a m m o n i a and dried over CaC12 in vacuo. This product on further drying at 80-90°C at 10 -4 torr for 8 hr u n d e r w e n t a color change from olive green to pale organge and then to the dark red-brown color of Pb(S2N2); m.p. 110°C dec. Extreme caution should be exercised in the handling of Pb(N2S2) as it detonates at ca 175 °. T h e IR spectra of these c o m p o u n d s were recorded on a Perkin E l m e r FIS-3 far IR spectrophotometer from 410
Normal coordinate analysis (NCA) has been carried on the complexes of C s and C~ symmetry for Pb(SzN2) and Pb(S2N2). NH3, respectively. The molecular parameters used for N C A were taken from the results of X-ray analysis [7]. For Pb(S2N2) the nine normal vibrations are classified into 7 A ' and 2A" all of which are IR and R a m a n active. T h e A' and A" modes are in-plane and out-ofplane vibrations, respectively. The programs written by Schachtschneider [8] were used in this work. Of the fifteen internal coordinates for Pb(S2Nz) (Table 1) ten are in-plane coordinates and five are torsion coordinates. The fifteen internal coordinates are further subdivided as follows: 5 stretching, 5 bending, and 5 torsional. The fifteen
138
Notes Table 3. Force constants (md//~) for Pb(S2N2)
Table 1. Internal coordinates for Pb(S2N2) 2
3
K(Pb--N) K(Pb--S) K(N1--S1) K(S~--N2) K(N2--S2) H(N--Pb--S) H(Pb--N--S)
N ml S Pb~"~/
nl
in-plane
torsion
2-1-5= 1-2-3
0.60 H(N--S---N) 0.90 H ( S - - N - - S ) 5.10 H ( P b - - S - - N ) 2.60 O(Pb--N) 3.70 O(N--S) 0.18 O(Pb--S) 0.72 O(N--N)
"rq
PU/
j2
2.3
2-3-4 4-5-1=/31 3-4-5= otI
q'l
3.4
\5
"g3
5.1
\2
\1
I
\S~ NI~
~'2
/4
j3 4.5
O(S----S) 0.10 F(N---S) 0.20 F(Pb--S) 0.40 F(N--N) 0.40 F(S--S) 0.20 F(Pb---N)0.10
N1--St
jl
= 01 = ~1
0.90 0.58 0.20 0.10 0.054 0.10 0.10
are in good agreement with that calculated by NCA. Table 4 also shows the predominant modes as well as the percent potential energy distribution (PED) for Pb(S2N2).
j5 1.2
\3 Table
RESULTS
"/'5
2. Symmetry coordinates (Pb(S2N2)
A' S 1 = AR 1 S 2 = Ar I 83 = Am I S4=An I S s = Ad 1
for
A" $6 = AffT1
$7 = AO1 $8 = A~ 1 59 = Aot 1 Slo = A/31
S l l = A,i-1
912 = 813 • S14 $15 =
A,~-2 AT3 A'r4 A~-s
symmetry coordinates which are given in Table 2 include six redundancies. These six redundancies are not easily eliminated and they were included in the N C A calculations. The calculated force constants; stretching (K), bending (H), repulsive (F) and out-of-plane (0) are displayed in Table 3. The interaction force constants (J) are not shown. The data on the IR spectrum of Pb(S2N2) is given in Table 4. It is particularly significant that the assignments
AND
DISCUSSION
As shown in Table 4 most of the observed frequencies are strongly coupled. For example, v3 at 6 6 4 c m -1 is assigned to a S r N 2 and S2-N 2 stretching and S---N--S bending mode. For the nonplanar ammoniate of Pb(S2N2) • NH 3 the 12 normal vibrational modes are of A symmetry (not including the hydrogens) and the nineteen internal coordinates are subdivided as follows: six stretching, seven bending, five torsion and one out-of-plane. The nineteen symmetry coordinates include seven redundancies which were included in the N C A calculations as they were not easily elminated. The ammonia group bonded to lead seems to have only a small effect on the ring atoms force constants. The five force constants showing any change from Pb(S2N2) to Pb(S2N2). NH 3 are: K(Pb--S), 0.90 to 0.80; K(N1--S1), 5.10 to 5.05; H ( P b - - N - - S ) , 0.72 to 0.83; O(Pb--N), 0.10 to 0.05 and O(N--S), 0.054 to 0.085. Similarly little or no change was observed in the IR spectrum of Pb(S2N2) • NH 3 as compared to the spectrum of Pb(S2N2). The Pb--N(NH3) stretch was observed at 305 cm -1 (calculated 305 cm -1) whereas the calculated out-of-plane Pb--N(NH3) at 55.4 cm -1 was not observed in the IR spectrum.
Acknowledgments--We thank the Marquette University Committee on Research, G. Y. Lin thanks the Arthur J. Schmitt Foundation for financial assistance and D. T. Haworth is grateful to Prof. H. J. Emeleus for his interest in this work.
Table 4. Comparison of observed and calculated frequencies and band assignments for Pb(S2N2)(cm -1) Observed
Calculated
v1 v2 v3 v4
982 907 664 550
982.5 906.9 665.0 549.0
v5 v6 v7 A " vs v9
346 235 183 279 --
346.1 235.2 182.4 279.2 177.3
A'
Predominant mode
Potential energy distribution (%)
v(N:--S1) v(Sl--N2) + v(S2----N2) V(Sl--N2) + v(S2--N2) + 8 ( S - - N - - S ) v(Pb---N) + v(S2--N2) + 8(Pb---N--S) + 8 (N--S---N) v(Pb--N) + 8 ( S - - N - - S ) v ( P b - - N ) + v(Pb--S)
$3(92) S4(25 ) + $5(67) $4(59) + S5(10 ) + $9(19) $1(14) + $5(11) + $7(37 ) + Ss(31) S 1(25) + Sq(32) $1(16) + $2(70 ) S1(43) + $6(26) + $1o(11) S11 (39) + $12(30) + $13(24) $11(16) + $13(29) + St4(25) + $1s(28)
v(Pb--N)+8(N--Pb--S)+8(Pb--S--N) II(Pb---N) + II(N--S) + II(Pb---S) II(Pb--N) + II(Pb--S) + H(N--N) + II(S--S)
Notes D. T. H A W O R T H G. Y. LIN
Department of Chemistry Marquette University Milwaukee, WI 53233 U.S.A.
REFERENCES
1. T. S. Piper, J. Am. Chem. Soc. 30, 80 (1958). 2. J. Weiss and U. Thewalt, Z. Anorg. Allgem. Chem. 363, 159 (1968). 3. D. T. Haworth and G. Y. Lin, J. Inorg. Nucl. Chem.
139
39, 1838 (1977). 4. D. T. Haworth, G. Y. Lin, J. D. Brown and J. Chen, Spectrochim. Acta 34A, 371 (1978). 5. O. Ruff and E. Geisel, Bet. dtsch. Chem. Ges. 37, 1573 (1904). 6. M. Goehring, J. Weiss and G. Zirker, Z. Anorg. Allgem. Chem. 278, 1 (1955). 7. J. Weiss, Z. Anorg. Allgem. Chem. 343, 315 (1966). 8. J. H. Schachtschneider, Vibrational Analysis of Polyatomic Molecules, Vols. V and V1, Technical Reports, Nos. 231-64 and 53-65, Shell Development Co., Emeryville, California (1964 and 1965).
[}022-1902/80/0101-() 1391502.00/0
J. inorg, n u c l Chem. Vol. -12, pp. 139 140
@ P er g amo n Press Ltd., |980. printed in Great Britain
Magnetic susceptibility of tetrametallic acetylacetonemono (o-hydroxyanil) copper (II) (Received 2 April 1979) In 1957, Kishita et al. [1] reported a subnormal magnetic moment of 1.37B.M. for the title compound. They suggested a dimeric structure for the molecules in which two copper atoms are very close to each other in order to account for the low magnetic moment. Harris and Kokot [2] measured the magnetic susceptibility of the compound over the temperature range 85-376°K, and indicated that the magnetic behavior could be interpreted on the basis of a dimetallic model. However, crystal structural results [3] determined that the molecules are actually tetrameric as shown in Fig. 1. The purpose of this work is to show that the magnetic behavior can be described if electron spinspin interactions among all four copper ions are taken into account.
The precipitate was washed with water, ethanol, and ether. The air-dried compound was recrystallized from bromobenzene [3]. Anal. Calc. for CI1HI102CuN: C, 52.26; H, 4.40; N, 5.54. Found: C, 52.42; H, 4.57; N, 5.42. The magnetic susceptibility was determined as a function of temperature with a Faraday system [4]. Mercury tetrathiocyanatocobalt(II) was used as the magnetic susceptibility standard [5], and appropriate diamagnetic corrections were estimated from Pascal's constants [6]. E P R spectra were obtained using a Varian E109E system operating at near 9.0 GHz. The field was calibrated using diphenyl-picrylhydrazyl (DPPH) for which g = 2.0036.
EXPERIMENTAL
The magnetic susceptibility as a function of temperature is shown in Fig. 2. The overall antiferromagnetic nature of the compound is clearly evident as the experimental magnetic moments, as calculated by the expression, P-err= 2.83(XM . . . . . T) t/2, decrease from 1.40 B.M. at 296 ° to only 0.20 B.M. at 77°K. The data were analyzed by the Bleaney-Bowers equation [7] for dimetallic
RESULTS A N D DISCUSSION
The Schitt base was prepared by reacting equimolar quantities of acetylacetone and o-aminophenol in ethanol. The mixture was heated at 65°C for 30 min, and on cooling, yellow crystals formed. The crystals were washed with ice-cold ethanol. Anal. Calc. for CIIHI302N: C, 69.08; H, 6.87; N, 7.33. Found: C, 69.18; H, 6.95; N, 7.30. Aqueous copper acetate monohydrate was mixed with an equimolar amount of the Schiff base in ethanol. The reaction was allowed to occur at 40°C for 30 min.
900
fo
O~N 30C
;°\ Fig. 1. A schematic representation of the structure of acetylacetonemono (o-hydroxyanil) copper(II).
IOC I~)0
I 200 T(*K)
I 300
Fig. 2. Magnetic susceptibility vs temperature for acetylacetonemono (o-hydroxyanil) copper (II). The circles represent experimental data with the solid line being the least-squares best fit to the tetramer equation and the dashed line being the least-squares best fit to the dimer equation.
Acknowledgements--One of the authors ( C R M Rao) is thankful to U.G.C. (India) for providing the financial assistance and the H e a d Chemistry d e p a r t m e n t for the research facilities. Department of Chemistry University of Roorkee Roorkee-24762, India
C. R A M A M O H A N R A O P. N. M E H R O T R A
REFERENCES 1. G. F. Huttig and E. L e h m a n n , Z. Phys. Chem. B19, 420 (1932). 2. J. Robin, Bull. Soc. Chim. Ft. 1078 (1953).
137
3. Y. A. Ugai, Zh. Obshch. Khim. 24, 1315 (1954). 4. V. P. Kornienko, Ukr. Khim. Zh. 23, 1996 (1957). 5. P. E. Yanwich and P. D. Zavitsanos, J. Phys. Chem. 68, 457 (1964). 6. L. Erdey and F. Paulik, Magy. Tudom. A k a d Kern. Tudom. Osztal. Kozl. 5, 461 (1955). 7. K. Kawagaki, J. Chem. Soc. Japan 72, 1079 (1951). 8. J. L. Doremieux and A. Boulle, Compt. Rend. 250, 3184 (1960). 9. D. Dollimore, J. Dollimore, and D. Nicholson. in Reactivity of solids (Edited by J. H. de Boer et al.) Proc. 4th Int. Symposium on the Reactivity of Solids. Elsevier, A m s t e r d a m (1961). 10. R. Sh. Mikhail, N. M. Guindy and 1. T. All, J. Appl. Chem. Biol. Technol 2,4, 583 (1974). 1 l. G. V. Subba Rao, M. Natarajan and C. N. R. Rao, J. Am. Ceram. Soc. 51, 179 (1968). 12. C. R a m a M o h a n Rao and P. N. Mehrotra. Ind. J. Chem. 15A, 1016 (1977). 13. D. Dollimore and D. Nicholson, J. Chem. Soc. 908 (1964). 14. C. R a m a M o h a n Rao and P. N. Mehrotra, l"hermo Chim Acta (in press). 15. H. J. Borchardt and F. Daniels, J. Am. (?hem. Sot'. 79, 41 (1957). 16. D. M. Speros and R. L. wood house, J. Phys. Chem. 72, 2846 (1968). 17. H. E. Kissinger, Analyt. Chem. 29, 1702 (1957L 18. K. J. Rao and C.N.R. Rao, J. Materials Sci. 1, 238 (1966). 19. C. R a m a M o h a n R a o and P. N. Mehrotra. Can. J. Chem. 56, 32 (1978).
J. inorg, nucl. Chem. Vok 42. pp. 137-139 ~) Pergamon Press Ltd,, 1980. Printed in Great Britain
0022-1902/80/0101-0137/$(12.00/0
A vibrational spectroscopy study of lead sulfur nitride (Received 30 March 1979) The reaction of a n h y d r o u s metal chlorides with tetrasulfur tetranitride in m e t h a n o l or ethanol has yielded three different c o m p o u n d s containing sulfur nitrogen bidentate ligands. These square planar c o m p o u n d s include M(SaNzH)2, M(S2N2H)(SaN) and M(S3N)2, when M is Ni, Pd or Pt [1-3]. W e have recently reported a comparison of their IR and R a m a n spectra using normal coordinate analysis [4]. W e now report our results of a vibrational study of the lead sulfur nitride, Pb(S2N2) and its ammoniate, Pb(S2N2) • N H 3.
to 3 3 c m -~ as nujol mulls on a polyethylene plate. The c o m p o u n d s were also run on a B e c k m a n IR-12 IR spectrophotometer from 4000-300 cm -1 using the K B r pellet technique. In both cases the spectra were obtained at room temperature and in a cold cell adaptable for use with the low frequency spectrophotometer. The instruments were calibrated by running the spectra of water vapor and polystyrene.
NORMAL COORDINATE ANALYSIS EXPE~NTAL The c o m p o u n d P b ( S 2 N z ) - N H 3 was prepared by the reaction of Pb(NO3) 2 with S 4 N 4 a t - 7 8 ° C in liquid amm o n i a [5, 6]. T h e olive green precipitate was washed with liquid a m m o n i a and dried over CaC12 in vacuo. This product on further drying at 80-90°C at 10 -4 torr for 8 hr u n d e r w e n t a color change from olive green to pale organge and then to the dark red-brown color of Pb(S2N2); m.p. 110°C dec. Extreme caution should be exercised in the handling of Pb(N2S2) as it detonates at ca 175 °. T h e IR spectra of these c o m p o u n d s were recorded on a Perkin E l m e r FIS-3 far IR spectrophotometer from 410
Normal coordinate analysis (NCA) has been carried on the complexes of C s and C~ symmetry for Pb(SzN2) and Pb(S2N2). NH3, respectively. The molecular parameters used for N C A were taken from the results of X-ray analysis [7]. For Pb(S2N2) the nine normal vibrations are classified into 7 A ' and 2A" all of which are IR and R a m a n active. T h e A' and A" modes are in-plane and out-ofplane vibrations, respectively. The programs written by Schachtschneider [8] were used in this work. Of the fifteen internal coordinates for Pb(S2Nz) (Table 1) ten are in-plane coordinates and five are torsion coordinates. The fifteen internal coordinates are further subdivided as follows: 5 stretching, 5 bending, and 5 torsional. The fifteen
138
Notes Table 3. Force constants (md//~) for Pb(S2N2)
Table 1. Internal coordinates for Pb(S2N2) 2
3
K(Pb--N) K(Pb--S) K(N1--S1) K(S~--N2) K(N2--S2) H(N--Pb--S) H(Pb--N--S)
N ml S Pb~"~/
nl
in-plane
torsion
2-1-5= 1-2-3
0.60 H(N--S---N) 0.90 H ( S - - N - - S ) 5.10 H ( P b - - S - - N ) 2.60 O(Pb--N) 3.70 O(N--S) 0.18 O(Pb--S) 0.72 O(N--N)
"rq
PU/
j2
2.3
2-3-4 4-5-1=/31 3-4-5= otI
q'l
3.4
\5
"g3
5.1
\2
\1
I
\S~ NI~
~'2
/4
j3 4.5
O(S----S) 0.10 F(N---S) 0.20 F(Pb--S) 0.40 F(N--N) 0.40 F(S--S) 0.20 F(Pb---N)0.10
N1--St
jl
= 01 = ~1
0.90 0.58 0.20 0.10 0.054 0.10 0.10
are in good agreement with that calculated by NCA. Table 4 also shows the predominant modes as well as the percent potential energy distribution (PED) for Pb(S2N2).
j5 1.2
\3 Table
RESULTS
"/'5
2. Symmetry coordinates (Pb(S2N2)
A' S 1 = AR 1 S 2 = Ar I 83 = Am I S4=An I S s = Ad 1
for
A" $6 = AffT1
$7 = AO1 $8 = A~ 1 59 = Aot 1 Slo = A/31
S l l = A,i-1
912 = 813 • S14 $15 =
A,~-2 AT3 A'r4 A~-s
symmetry coordinates which are given in Table 2 include six redundancies. These six redundancies are not easily eliminated and they were included in the N C A calculations. The calculated force constants; stretching (K), bending (H), repulsive (F) and out-of-plane (0) are displayed in Table 3. The interaction force constants (J) are not shown. The data on the IR spectrum of Pb(S2N2) is given in Table 4. It is particularly significant that the assignments
AND
DISCUSSION
As shown in Table 4 most of the observed frequencies are strongly coupled. For example, v3 at 6 6 4 c m -1 is assigned to a S r N 2 and S2-N 2 stretching and S---N--S bending mode. For the nonplanar ammoniate of Pb(S2N2) • NH 3 the 12 normal vibrational modes are of A symmetry (not including the hydrogens) and the nineteen internal coordinates are subdivided as follows: six stretching, seven bending, five torsion and one out-of-plane. The nineteen symmetry coordinates include seven redundancies which were included in the N C A calculations as they were not easily elminated. The ammonia group bonded to lead seems to have only a small effect on the ring atoms force constants. The five force constants showing any change from Pb(S2N2) to Pb(S2N2). NH 3 are: K(Pb--S), 0.90 to 0.80; K(N1--S1), 5.10 to 5.05; H ( P b - - N - - S ) , 0.72 to 0.83; O(Pb--N), 0.10 to 0.05 and O(N--S), 0.054 to 0.085. Similarly little or no change was observed in the IR spectrum of Pb(S2N2) • NH 3 as compared to the spectrum of Pb(S2N2). The Pb--N(NH3) stretch was observed at 305 cm -1 (calculated 305 cm -1) whereas the calculated out-of-plane Pb--N(NH3) at 55.4 cm -1 was not observed in the IR spectrum.
Acknowledgments--We thank the Marquette University Committee on Research, G. Y. Lin thanks the Arthur J. Schmitt Foundation for financial assistance and D. T. Haworth is grateful to Prof. H. J. Emeleus for his interest in this work.
Table 4. Comparison of observed and calculated frequencies and band assignments for Pb(S2N2)(cm -1) Observed
Calculated
v1 v2 v3 v4
982 907 664 550
982.5 906.9 665.0 549.0
v5 v6 v7 A " vs v9
346 235 183 279 --
346.1 235.2 182.4 279.2 177.3
A'
Predominant mode
Potential energy distribution (%)
v(N:--S1) v(Sl--N2) + v(S2----N2) V(Sl--N2) + v(S2--N2) + 8 ( S - - N - - S ) v(Pb---N) + v(S2--N2) + 8(Pb---N--S) + 8 (N--S---N) v(Pb--N) + 8 ( S - - N - - S ) v ( P b - - N ) + v(Pb--S)
$3(92) S4(25 ) + $5(67) $4(59) + S5(10 ) + $9(19) $1(14) + $5(11) + $7(37 ) + Ss(31) S 1(25) + Sq(32) $1(16) + $2(70 ) S1(43) + $6(26) + $1o(11) S11 (39) + $12(30) + $13(24) $11(16) + $13(29) + St4(25) + $1s(28)
v(Pb--N)+8(N--Pb--S)+8(Pb--S--N) II(Pb---N) + II(N--S) + II(Pb---S) II(Pb--N) + II(Pb--S) + H(N--N) + II(S--S)
Notes D. T. H A W O R T H G. Y. LIN
Department of Chemistry Marquette University Milwaukee, WI 53233 U.S.A.
REFERENCES
1. T. S. Piper, J. Am. Chem. Soc. 30, 80 (1958). 2. J. Weiss and U. Thewalt, Z. Anorg. Allgem. Chem. 363, 159 (1968). 3. D. T. Haworth and G. Y. Lin, J. Inorg. Nucl. Chem.
139
39, 1838 (1977). 4. D. T. Haworth, G. Y. Lin, J. D. Brown and J. Chen, Spectrochim. Acta 34A, 371 (1978). 5. O. Ruff and E. Geisel, Bet. dtsch. Chem. Ges. 37, 1573 (1904). 6. M. Goehring, J. Weiss and G. Zirker, Z. Anorg. Allgem. Chem. 278, 1 (1955). 7. J. Weiss, Z. Anorg. Allgem. Chem. 343, 315 (1966). 8. J. H. Schachtschneider, Vibrational Analysis of Polyatomic Molecules, Vols. V and V1, Technical Reports, Nos. 231-64 and 53-65, Shell Development Co., Emeryville, California (1964 and 1965).
[}022-1902/80/0101-() 1391502.00/0
J. inorg, n u c l Chem. Vol. -12, pp. 139 140
@ P er g amo n Press Ltd., |980. printed in Great Britain
Magnetic susceptibility of tetrametallic acetylacetonemono (o-hydroxyanil) copper (II) (Received 2 April 1979) In 1957, Kishita et al. [1] reported a subnormal magnetic moment of 1.37B.M. for the title compound. They suggested a dimeric structure for the molecules in which two copper atoms are very close to each other in order to account for the low magnetic moment. Harris and Kokot [2] measured the magnetic susceptibility of the compound over the temperature range 85-376°K, and indicated that the magnetic behavior could be interpreted on the basis of a dimetallic model. However, crystal structural results [3] determined that the molecules are actually tetrameric as shown in Fig. 1. The purpose of this work is to show that the magnetic behavior can be described if electron spinspin interactions among all four copper ions are taken into account.
The precipitate was washed with water, ethanol, and ether. The air-dried compound was recrystallized from bromobenzene [3]. Anal. Calc. for CI1HI102CuN: C, 52.26; H, 4.40; N, 5.54. Found: C, 52.42; H, 4.57; N, 5.42. The magnetic susceptibility was determined as a function of temperature with a Faraday system [4]. Mercury tetrathiocyanatocobalt(II) was used as the magnetic susceptibility standard [5], and appropriate diamagnetic corrections were estimated from Pascal's constants [6]. E P R spectra were obtained using a Varian E109E system operating at near 9.0 GHz. The field was calibrated using diphenyl-picrylhydrazyl (DPPH) for which g = 2.0036.
EXPERIMENTAL
The magnetic susceptibility as a function of temperature is shown in Fig. 2. The overall antiferromagnetic nature of the compound is clearly evident as the experimental magnetic moments, as calculated by the expression, P-err= 2.83(XM . . . . . T) t/2, decrease from 1.40 B.M. at 296 ° to only 0.20 B.M. at 77°K. The data were analyzed by the Bleaney-Bowers equation [7] for dimetallic
RESULTS A N D DISCUSSION
The Schitt base was prepared by reacting equimolar quantities of acetylacetone and o-aminophenol in ethanol. The mixture was heated at 65°C for 30 min, and on cooling, yellow crystals formed. The crystals were washed with ice-cold ethanol. Anal. Calc. for CIIHI302N: C, 69.08; H, 6.87; N, 7.33. Found: C, 69.18; H, 6.95; N, 7.30. Aqueous copper acetate monohydrate was mixed with an equimolar amount of the Schiff base in ethanol. The reaction was allowed to occur at 40°C for 30 min.
900
fo
O~N 30C
;°\ Fig. 1. A schematic representation of the structure of acetylacetonemono (o-hydroxyanil) copper(II).
IOC I~)0
I 200 T(*K)
I 300
Fig. 2. Magnetic susceptibility vs temperature for acetylacetonemono (o-hydroxyanil) copper (II). The circles represent experimental data with the solid line being the least-squares best fit to the tetramer equation and the dashed line being the least-squares best fit to the dimer equation.