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Sodium lanthanide oxides NaLnO2
2444
Notes
3. lnorg, nucl. Chem., 1966, Vol. 28, pp. 2444 to 2445. Pergamon Press Ltd. Printed in Northern Ireland
Sodium lanthanide oxides N a L n O s (Received 8 April 1966) Tins note reports crystallographic data on sodium lanthanide oxides NaLnOs. Only the structures of the compounds NaGdO~ and NaYO~ have beenreported earlier, tt,s~whereas the existence of NaLaOt has been mentioned:a) Samples were prepared by heating intimate mixtures of anhydrous NaaCO, and lanthanide oxides Ln~Ot for 4 hr at 1100°C in dry air. X-ray powder diagrams were obtained on a Philips diffractometer using CuK~-radiation. Results are presented in Table 1. TASLE 1.--SURVEY OF CRYSTALLOGRAPHICRF~ULT$ Compound
Structure
rr.ns+ (A)*
NaLaOs NaNdOs NaSmOs NaEuOs NaGdOs NaTbOs NaDyOs NaHoO, NaErOs NaTmO~ NaYbOs NaLuOg NaYOa NaScOI NaInOl
cc-LiFeOi x-LiFeOs c¢-LiFeOs c~-LiFeOa ~-LiFeOa ~-LiFeOI fl-LiFeOs fl-LiFeOs ~-LiFeOi --NaFeOa u-NaFeOs u-NaFeO2 x-NaFeOa u-NaFeO~ u-NaFeOe
1.14 1.04 1.00 0-98 0.97 0.93 0.92 0.91 0"89 0.87 0.86 0.85 0.92 0.81 0.81
Lattice parameters (A) a c
References
4.80 4.74 4.69 4-67 4.66
11.29 10-88 10.62 10-57 10.53
1
3.35 3.33 3.32 3-39 3.17 3-23
16.58 16.55 16.52 16"43 16.27 16.39
2 2 2
* According to L. H. AHm~m, Geochim. cosmoehim. Acta 2, 155 (1952). rl~a+ = 0"94A.
All compounds have an ordered rocksalt lattice. If the ionic radius of the Lns÷ ion is larger than that of the Na + ion (Los+ up to Gda+), the cc-LiFeO2structure is found. This structure is tetragonal and has a unit cell twice as large as that of the statistical rocksalt structure. If the Lns+ ion is a little smaller than Na + (Tbs+ up to EO+), an X-ray pattern similar to that of fl-LiFeOs is found. This structure is not known at the moment. If the Ln~+ ion is considerably smaller than Na+(Tms+ up to Lus+, including ys+, ScS+, inS+), the hexagonal ~-NaFeO2 structure is found. In this structure the (111) cation-layers are occupied alternatively by Na + and Lns+ ions. The fl-LiFeO1 structure was first found by COLLONGUeSc4~for LiFeOi. His structure proposal is certainly wrong, because it is impossible to index the X-ray patterns on the proposed unit cell. Moreover the experimental intensities do not agree with those calculated. ~6~ On the other hand it seems obvious to consider fl-LiFeOz as an ordered rocksalt lattice, since all reflections to be expected for such a lattice are present in the diagram. The structure of part of the compounds is influenced by small amounts of other lanthanides: NaGdO~ has c~-LiFeO2structure, NaGd0.95Tb0.0~O~has fl-LiFeOz structure; NaErOz has ~-LiFeO~ (i) G. BLASE, J. inorg, nucL Chem. 26, 901 (1964). (a) R. HOPPE, Bull. See. chim. Ft. 1115, (1965). ca) E. ZIm'L, Z. anorg, allg. Chem. 24.5, 26 (1940). c4~M. FAYARD,Bull. Soe. chim. Fr. 1121, (1965); R. 241, 1577 (1955). ~s) C. J. M. ROOYMAm,Private communication.
COLLONGUES,
C. r. hebd. Sdane. Acad. Sci., Paris
Notes
2445
TABLE 2 . - - X - R A Y DIAGRAM OF NaY0.96Euo.osO2 (COPPER RADIATION)
d(A)
int.
d(A)
int.
5'12 3.42 2.87 2"77 2.74 2.50 2.37 2.34 2.12
s m w m s s w vs w
1"94 1.90 1.78 1-75 1.72 1.70 1.65 1.59
w w w w m m m w
structure, NaEro.osLuo.0502 has ~t-NaFeOs structure; NaYO~ has g-NaFeO~ structure, NaYo.osEuo.obO2 has fl-LiFeOz structure. Many of the compounds NaLnO2 are probably polymorphous (see also Reference 2). From the fluorescence emission of NaYo.osEuo.o~O~ it can be deduced that there are at least two crystallographic lanthanide sites in this compound, which lack inversion symmetry.c6~ The X-ray pattern of this composition (fl-LiFeO~ structure) is given in Table 2.
Acknowledgement--The author is indebted to Mr. J. DE VRIES, who assisted in the preparation. Philips Research Laboratories iV. V. Philips' Gloeilampenfabrieken Eindhoven-Netherlands
G. BLASSE
~ G. BLASSEand A. BpaL, to be published.
J. inorg, nucl. Chem., 1966, Vol. 28, pp. 2445 to 2447. Pergamon Press Ltd. Printed in Northern Ireland
T r i a r y l t i n isothiocyanates
(Received 10 March 1966) A CONSIDERABLEamount of work has been reported on the preparation, a-4~ structure ts~ and complexes ~e~of alkyltin isothiocyanates.* But there is no reference to the corresponding aryltin compounds excepting for a brief mention of the preparation of triphenyltin isothiocyanate by SRIVASTAVA and TANI~N,~7) This paper describes the preparation and properties of two new triaryltinisothiocayantes. On the basis of infra-red studies it is suggested that these are predominantly covalent compounds and possess an iso (--NCS) grouping. Attempts at the preparation of tribenzyltin isothioeyanate failed to yield the pure compound. * The word iso leaves open the question as to whether the group is nitrogen or sulphur bonded. ~x~H. H. ANDEa.SONand J. VASTA,Y. org. Chem. 19, 1300 (1954). c8~D. SEY~tTH and N. ~ , Y. org. Chem. 25, 809 (1960). ~s~ D. SE~T~TH and E. G. ROCHOW, J. Am. chem. Soc. 77, 1302 (1955). ~ D. L. ~ N , A. G. DAVI~, M. HANCOCK and R. F. M. WnrrE, J. chem. Soc. 5469 (1963). cb) R. A. ~ and P. Dt~N, Austr. Y. Chem. 17, 411 (1964). ce~ M. WADA, M. N ~ I r ~ and R. O g ~ w A ~ , J. organomet. Chem. 3, 70 (1965). c7~T. N. SRIVASTAVAand S. K. TANDON,Ind. J. appl. Chem. 26, 171 (1963).
Notes
3. lnorg, nucl. Chem., 1966, Vol. 28, pp. 2444 to 2445. Pergamon Press Ltd. Printed in Northern Ireland
Sodium lanthanide oxides N a L n O s (Received 8 April 1966) Tins note reports crystallographic data on sodium lanthanide oxides NaLnOs. Only the structures of the compounds NaGdO~ and NaYO~ have beenreported earlier, tt,s~whereas the existence of NaLaOt has been mentioned:a) Samples were prepared by heating intimate mixtures of anhydrous NaaCO, and lanthanide oxides Ln~Ot for 4 hr at 1100°C in dry air. X-ray powder diagrams were obtained on a Philips diffractometer using CuK~-radiation. Results are presented in Table 1. TASLE 1.--SURVEY OF CRYSTALLOGRAPHICRF~ULT$ Compound
Structure
rr.ns+ (A)*
NaLaOs NaNdOs NaSmOs NaEuOs NaGdOs NaTbOs NaDyOs NaHoO, NaErOs NaTmO~ NaYbOs NaLuOg NaYOa NaScOI NaInOl
cc-LiFeOi x-LiFeOs c¢-LiFeOs c~-LiFeOa ~-LiFeOa ~-LiFeOI fl-LiFeOs fl-LiFeOs ~-LiFeOi --NaFeOa u-NaFeOs u-NaFeO2 x-NaFeOa u-NaFeO~ u-NaFeOe
1.14 1.04 1.00 0-98 0.97 0.93 0.92 0.91 0"89 0.87 0.86 0.85 0.92 0.81 0.81
Lattice parameters (A) a c
References
4.80 4.74 4.69 4-67 4.66
11.29 10-88 10.62 10-57 10.53
1
3.35 3.33 3.32 3-39 3.17 3-23
16.58 16.55 16.52 16"43 16.27 16.39
2 2 2
* According to L. H. AHm~m, Geochim. cosmoehim. Acta 2, 155 (1952). rl~a+ = 0"94A.
All compounds have an ordered rocksalt lattice. If the ionic radius of the Lns÷ ion is larger than that of the Na + ion (Los+ up to Gda+), the cc-LiFeO2structure is found. This structure is tetragonal and has a unit cell twice as large as that of the statistical rocksalt structure. If the Lns+ ion is a little smaller than Na + (Tbs+ up to EO+), an X-ray pattern similar to that of fl-LiFeOs is found. This structure is not known at the moment. If the Ln~+ ion is considerably smaller than Na+(Tms+ up to Lus+, including ys+, ScS+, inS+), the hexagonal ~-NaFeO2 structure is found. In this structure the (111) cation-layers are occupied alternatively by Na + and Lns+ ions. The fl-LiFeO1 structure was first found by COLLONGUeSc4~for LiFeOi. His structure proposal is certainly wrong, because it is impossible to index the X-ray patterns on the proposed unit cell. Moreover the experimental intensities do not agree with those calculated. ~6~ On the other hand it seems obvious to consider fl-LiFeOz as an ordered rocksalt lattice, since all reflections to be expected for such a lattice are present in the diagram. The structure of part of the compounds is influenced by small amounts of other lanthanides: NaGdO~ has c~-LiFeO2structure, NaGd0.95Tb0.0~O~has fl-LiFeOz structure; NaErOz has ~-LiFeO~ (i) G. BLASE, J. inorg, nucL Chem. 26, 901 (1964). (a) R. HOPPE, Bull. See. chim. Ft. 1115, (1965). ca) E. ZIm'L, Z. anorg, allg. Chem. 24.5, 26 (1940). c4~M. FAYARD,Bull. Soe. chim. Fr. 1121, (1965); R. 241, 1577 (1955). ~s) C. J. M. ROOYMAm,Private communication.
COLLONGUES,
C. r. hebd. Sdane. Acad. Sci., Paris
Notes
2445
TABLE 2 . - - X - R A Y DIAGRAM OF NaY0.96Euo.osO2 (COPPER RADIATION)
d(A)
int.
d(A)
int.
5'12 3.42 2.87 2"77 2.74 2.50 2.37 2.34 2.12
s m w m s s w vs w
1"94 1.90 1.78 1-75 1.72 1.70 1.65 1.59
w w w w m m m w
structure, NaEro.osLuo.0502 has ~t-NaFeOs structure; NaYO~ has g-NaFeO~ structure, NaYo.osEuo.obO2 has fl-LiFeOz structure. Many of the compounds NaLnO2 are probably polymorphous (see also Reference 2). From the fluorescence emission of NaYo.osEuo.o~O~ it can be deduced that there are at least two crystallographic lanthanide sites in this compound, which lack inversion symmetry.c6~ The X-ray pattern of this composition (fl-LiFeO~ structure) is given in Table 2.
Acknowledgement--The author is indebted to Mr. J. DE VRIES, who assisted in the preparation. Philips Research Laboratories iV. V. Philips' Gloeilampenfabrieken Eindhoven-Netherlands
G. BLASSE
~ G. BLASSEand A. BpaL, to be published.
J. inorg, nucl. Chem., 1966, Vol. 28, pp. 2445 to 2447. Pergamon Press Ltd. Printed in Northern Ireland
T r i a r y l t i n isothiocyanates
(Received 10 March 1966) A CONSIDERABLEamount of work has been reported on the preparation, a-4~ structure ts~ and complexes ~e~of alkyltin isothiocyanates.* But there is no reference to the corresponding aryltin compounds excepting for a brief mention of the preparation of triphenyltin isothiocyanate by SRIVASTAVA and TANI~N,~7) This paper describes the preparation and properties of two new triaryltinisothiocayantes. On the basis of infra-red studies it is suggested that these are predominantly covalent compounds and possess an iso (--NCS) grouping. Attempts at the preparation of tribenzyltin isothioeyanate failed to yield the pure compound. * The word iso leaves open the question as to whether the group is nitrogen or sulphur bonded. ~x~H. H. ANDEa.SONand J. VASTA,Y. org. Chem. 19, 1300 (1954). c8~D. SEY~tTH and N. ~ , Y. org. Chem. 25, 809 (1960). ~s~ D. SE~T~TH and E. G. ROCHOW, J. Am. chem. Soc. 77, 1302 (1955). ~ D. L. ~ N , A. G. DAVI~, M. HANCOCK and R. F. M. WnrrE, J. chem. Soc. 5469 (1963). cb) R. A. ~ and P. Dt~N, Austr. Y. Chem. 17, 411 (1964). ce~ M. WADA, M. N ~ I r ~ and R. O g ~ w A ~ , J. organomet. Chem. 3, 70 (1965). c7~T. N. SRIVASTAVAand S. K. TANDON,Ind. J. appl. Chem. 26, 171 (1963).