- Email: [email protected]
Comparison of infrared spectra of organophosphorus acids and their sodium salts
Notes
377
Comparison of infrared spectra of organophosphorus acids and their sodium salts* (Received 26 September 1963) IN A recent publication, tx' the infrared spectra of organophosphoric acids and their sodium salts were compared. Various changes that occurred in going from the acid to the salt spectra were discussed. In this paper, similar comparisons were made for 8 half esters of phosphonic acids of the type (GO)G'PO(OH), and 2 phosphinic acids of the type GG'PO(OH). The results are tabulated in Table 1. TABLE 1.--COMPARISONOF
INFRARED ABSORPTIONS IN ORGANOPHOSPHORUS ACIDS AND THEIR SODIUM SALTS
Absorption s Present in acids" and salts e
Compound (GO)G'PO(OH)
New absorption present only in salts
(cm- l) 1180 (M-S)
1140 (M-S)
+
-'-
G
G'
1440 (M-S)
p'C,H17-~'-
CICH2-
-
4,CH~-
~-
q
+
+ ~ -÷ q -
-~ + + ~-
butyl9~cyclohexyl~tridecyl~2-ethylhexyl~2-ethylhexyl2-ethylhexyl GG'POOH a G G' ~~-
-~
-
_
(cm-1) 930 (M-S)
+
+ absorption occurs - - absence of absorption (M-S) medium to strong intensity a Infrared spectra on KBr discs and checked by Nujol mulls were made with a Perkin-Elmer No. 221 Spectrophotometer and a No. 237 Infrared Spectrophotometer. b Acids prepared by methods already described, t2' e Salts prepared from acids by electrometric titration with alcoholic NaOH. a Diphenyl phosphinic acid and phenyl hydrogen phosphinic acid were obtained from Victor Chemical Works. In general, the salt spectra are sharper, because of the removal of the hydrogen bonding present in the acids. There are six regions of interest, and these are as follows: 1 . All compounds having a ¢~-P link had absorption in the 1440 cm -1 region, substantiating the results of DAA$CH and SMITH. {8} 2 . Absorption in the acids at about 1200 cm -1 is replaced on salt formation by new absorption in the region of 1 175-1250 cm -1 and 1050-1100 cm -~, presumably the POO- asymmetric and symmetric vibrations,"' respectively. * Based on work performed under the auspices of the U.S. Atomic Energy Commission. "~ J. R. FERRARO,J. lnorg. Nucl. Chem. 24, 475 (1962). t~ D. F. PEPeARD, J. R. FERRAROand G. W. MASON,J. Inorg. Nu¢l. Chem. 12, 60 (1959). ,s~ L. W. DAASCHand D. C. SMn'H, Analyt. Chem. 23, 853 (1951).
378
Notes
3. In the two compounds with ~R:)P links, absorption has been found in the 1180 cm -x region, and this has been attributed to the (~bO)P vibration. ~'~ 4. Absorption in the 1140 cm -x region is cited. The nature of this absorption is not known, but it appears to he present in compounds containing phenyl groups. 5. Absorption in the acids in the 900-1000 cm -1 region has been attributed to the (P-O)-H and P-C(aryl) vibrations. Upon salt formation some dimunition of absorption occurs in this region. New absorption at lower frequency (,,..930 cm -~) occurs only for compounds with a P-O-C(aryl) link. m 6. In some salt spectra, new weak absorption is observed in the 800-825 cm -x region.
AcknowledKement--The authors wish to express their appreciation to Mr. George W. Mason of Argonne National Laboratory for the preparation of the acids from which the salts were prepared.
Argonne National Laboratory 9700 South Cass Avenue Argonne, Illinois
J . R . F~RPa~RO C . M . ANDRmASlCH
~4~L. J. BELLAMYand L. BEECr~R, J. Chem. Soc. 476, 1701 (1952).
A conductometric-amperometric study of cadmium cobalticyanide (Received 18 May 1963; in revised form 24 September 1963) CADMIUM reacts stoichiometrically with cobalticyanide as shown by conductometric and amperometric titrations. The solubility of the complex Cda[Co(CN)d, and the dissociation constant of the ion-pair have been determined at 25°C from conductivity measurements.
Apparatus Amperometric titrations were carried out with a manual set-up using an H-ceU with a saturated calomel electrode as the reference electrode. JoN~ and Jos~PnS ~1~ conductivity bridge fabricated here was used with a Tektronix type 502 oscilloscope as a null detector. A Washburn cell (Cenco 70015A) was used for the measurement of equivalent conductances. Experiments were carried out at 25 -4- 0.01°C using a Townson and Mercer thermostat (Type X27) with a refrigeration unit.
Chemicals Cadmium sulphate (AnalaR grade) and potassium cobalticyanide (BDH) recrystallized from a water--dioxane mixture were used for preparing the stock solutions. Conductivity water having a specific conductance of 0.7 × 10-6 f2-~ cm -1 was used.
Amperometric and conductometric titrations Amperometric and conductometric titrations of different aliquots of cadmium sulphate solution were carried out. The results of both forward and reverse titrations are given in Tables 1 and 2 and Figs. 1 and 2. It is seen that the ratio of Cd ~6 to Co(CN)c s at the inflection points is 1"5 and the formula of the complex is Cds[Co(CN),],.
Measurement of equivalent conductance Cadmium cobalticyanide, precipitated from solutions of cadmium sulphate and potassium cobalticyanide prepared in conductivity water, was filtered, washed well and was kept suspended in conductivity water for several days with frequent renewal of water. The sample was then filtered and dried in vacuo. The resistances of the solutions obtained from two stock solutions of cadmium cobalticyanide were measured. The results are given in Table 3. ~x~G. JONES and R. C. JosEPns, J. Amer. Chem. Soc. 50, 1049 (1928).
377
Comparison of infrared spectra of organophosphorus acids and their sodium salts* (Received 26 September 1963) IN A recent publication, tx' the infrared spectra of organophosphoric acids and their sodium salts were compared. Various changes that occurred in going from the acid to the salt spectra were discussed. In this paper, similar comparisons were made for 8 half esters of phosphonic acids of the type (GO)G'PO(OH), and 2 phosphinic acids of the type GG'PO(OH). The results are tabulated in Table 1. TABLE 1.--COMPARISONOF
INFRARED ABSORPTIONS IN ORGANOPHOSPHORUS ACIDS AND THEIR SODIUM SALTS
Absorption s Present in acids" and salts e
Compound (GO)G'PO(OH)
New absorption present only in salts
(cm- l) 1180 (M-S)
1140 (M-S)
+
-'-
G
G'
1440 (M-S)
p'C,H17-~'-
CICH2-
-
4,CH~-
~-
q
+
+ ~ -÷ q -
-~ + + ~-
butyl9~cyclohexyl~tridecyl~2-ethylhexyl~2-ethylhexyl2-ethylhexyl GG'POOH a G G' ~~-
-~
-
_
(cm-1) 930 (M-S)
+
+ absorption occurs - - absence of absorption (M-S) medium to strong intensity a Infrared spectra on KBr discs and checked by Nujol mulls were made with a Perkin-Elmer No. 221 Spectrophotometer and a No. 237 Infrared Spectrophotometer. b Acids prepared by methods already described, t2' e Salts prepared from acids by electrometric titration with alcoholic NaOH. a Diphenyl phosphinic acid and phenyl hydrogen phosphinic acid were obtained from Victor Chemical Works. In general, the salt spectra are sharper, because of the removal of the hydrogen bonding present in the acids. There are six regions of interest, and these are as follows: 1 . All compounds having a ¢~-P link had absorption in the 1440 cm -1 region, substantiating the results of DAA$CH and SMITH. {8} 2 . Absorption in the acids at about 1200 cm -1 is replaced on salt formation by new absorption in the region of 1 175-1250 cm -1 and 1050-1100 cm -~, presumably the POO- asymmetric and symmetric vibrations,"' respectively. * Based on work performed under the auspices of the U.S. Atomic Energy Commission. "~ J. R. FERRARO,J. lnorg. Nucl. Chem. 24, 475 (1962). t~ D. F. PEPeARD, J. R. FERRAROand G. W. MASON,J. Inorg. Nu¢l. Chem. 12, 60 (1959). ,s~ L. W. DAASCHand D. C. SMn'H, Analyt. Chem. 23, 853 (1951).
378
Notes
3. In the two compounds with ~R:)P links, absorption has been found in the 1180 cm -x region, and this has been attributed to the (~bO)P vibration. ~'~ 4. Absorption in the 1140 cm -x region is cited. The nature of this absorption is not known, but it appears to he present in compounds containing phenyl groups. 5. Absorption in the acids in the 900-1000 cm -1 region has been attributed to the (P-O)-H and P-C(aryl) vibrations. Upon salt formation some dimunition of absorption occurs in this region. New absorption at lower frequency (,,..930 cm -~) occurs only for compounds with a P-O-C(aryl) link. m 6. In some salt spectra, new weak absorption is observed in the 800-825 cm -x region.
AcknowledKement--The authors wish to express their appreciation to Mr. George W. Mason of Argonne National Laboratory for the preparation of the acids from which the salts were prepared.
Argonne National Laboratory 9700 South Cass Avenue Argonne, Illinois
J . R . F~RPa~RO C . M . ANDRmASlCH
~4~L. J. BELLAMYand L. BEECr~R, J. Chem. Soc. 476, 1701 (1952).
A conductometric-amperometric study of cadmium cobalticyanide (Received 18 May 1963; in revised form 24 September 1963) CADMIUM reacts stoichiometrically with cobalticyanide as shown by conductometric and amperometric titrations. The solubility of the complex Cda[Co(CN)d, and the dissociation constant of the ion-pair have been determined at 25°C from conductivity measurements.
Apparatus Amperometric titrations were carried out with a manual set-up using an H-ceU with a saturated calomel electrode as the reference electrode. JoN~ and Jos~PnS ~1~ conductivity bridge fabricated here was used with a Tektronix type 502 oscilloscope as a null detector. A Washburn cell (Cenco 70015A) was used for the measurement of equivalent conductances. Experiments were carried out at 25 -4- 0.01°C using a Townson and Mercer thermostat (Type X27) with a refrigeration unit.
Chemicals Cadmium sulphate (AnalaR grade) and potassium cobalticyanide (BDH) recrystallized from a water--dioxane mixture were used for preparing the stock solutions. Conductivity water having a specific conductance of 0.7 × 10-6 f2-~ cm -1 was used.
Amperometric and conductometric titrations Amperometric and conductometric titrations of different aliquots of cadmium sulphate solution were carried out. The results of both forward and reverse titrations are given in Tables 1 and 2 and Figs. 1 and 2. It is seen that the ratio of Cd ~6 to Co(CN)c s at the inflection points is 1"5 and the formula of the complex is Cds[Co(CN),],.
Measurement of equivalent conductance Cadmium cobalticyanide, precipitated from solutions of cadmium sulphate and potassium cobalticyanide prepared in conductivity water, was filtered, washed well and was kept suspended in conductivity water for several days with frequent renewal of water. The sample was then filtered and dried in vacuo. The resistances of the solutions obtained from two stock solutions of cadmium cobalticyanide were measured. The results are given in Table 3. ~x~G. JONES and R. C. JosEPns, J. Amer. Chem. Soc. 50, 1049 (1928).