Metal( II) Chloride Complexes of N-Methylformamide RAYMOND A. MACKAY and EDWARD J. POZIOMEK Physical Research Laboratory, Edgewood Arsenal, Md.
21 010
The preparation and properties of some N-methylformamide complexes of MClz (M = Mg, Mn, Co, Ni, Cu, Zn, and Cd) are described.
I N THE course of studies on reactions of coordinated formamides ( I ) , a series of metal chloride complexes of N-methylformamide ( N M F ) was prepared and characterized. T h e compounds and analytical d a t a are given in Table I. A number of physical properties are given in
Table 11. The shift of the carbonyl stretching bands to lower frequency relative t o N M F shows t h a t coordination occurs via oxygen ( I ) . T h e structures of the Co, Ni, and Cu complexes are based on electronic spectra (Table 111). T h e complexes are hydrolyzed by water, and are a t least
Table I . Analyses Found Compound MgCln(NMF),(H20)n MnCla (NMF)2 COCI~(NMF)J NiCL (NMF)I CuClz(NMF)n ZnC12(NMF)z ZnL (NMF), CdCL(NMF)z
Calculated N
C
H
N
c1
M
C
H
26.6 19.4 24.0 26.1 18.9 19.3
6.7 4.9 5.2 5.8 4.0 3.9 2.3 3.4
14.9 11.7 13.5 15.2 11.5 10.5 6.0 9.2
19.8 29.2 23.9 19.7 28.3 28.2 57.9" 23.9
6.2 13.4 18.9 16.5 25.2 25.7 14.7 37.4
26.2 19.7 23.4 26.2 19.0 18.9 11.0 15.9
6.5 4.1 4.9 5.5 4.0 3.9 2.3 3.3
11.0
15.7
15.2 11.5 13.7 15.3 11.1
11.0 6.4 9.3
c1
M
19.3 29.1 23.2 19.4 28.1 27.9 58.1" 23.6
6.6 13.1 19.2 16.1 25.1 25.7 14.9 37.3
Iodine. Table II. Physical Properties Compound
Probable Structure
[ Mg(NMF)4CIz]* 2Hz0
Octahedral Octahedralpolymeric [ CO(NMF)~][COC~I ] (act) (tet) Octahedral Square planar or tetragonal Tetrahedral Tetrahedral Tetrahedral
MnC12(NMF)z Co(NMF)1C1z [Ni(r\iMF)4C1z] [Cu(NMF)zClz] [Zn(NMF)zCL] [ Zn(NMF)2 1 2 jCd(NMF)zC1z] "Cm.
I.
'A" =
YhhfF
uc=o
Color
-6
NO
Hygroscopic
-18
130-34' 12gd
1650
-22
130-32
White Light pink Blue
1646 1642
-26 -30
127' 112'
Yellow Green
Yes Slightly
1650 1645 1653
-22 -27 -19
88-90 76-80' > 250
White White White
No No No
Yes No
Errors on frequencies ca. &4 cm.-'. Spectra run as Nujol mulls between KRS-5 windows on Perkin-Elmer 257 spectrophotometer. - Y complex. uSMF = 1672 cm. - I . Softens over wide range. Decomposes without melting.
COC12(NMF)3
NiC12(NMF)
1612
(mw) 1257
CuClz (NMF)z 810 (broad)
(mw) 1558 (sh-b) 710 (m)
(w)
M.P., "C.
1666 1654
Table Ill. Electronic Spectra"
(s)
Abob
698 670 650 630 616
(sh)
533 516 459
(sh) (sh)
790
(ms) 421
"Solids as Nujol mulls on Cary 14 spectrophotometer: w = weak, m = medium, s = strong, sh = shoulder, b = broad. Range 300 to 1700 mp.
VOL. 14, No. 2, APRIL 1969
somewhat soluble in polar organic solvents-e.g., ethanol, nitromethane, and butanol-except t h a t the manganese compound is generally insoluble. T h e electronic spectra were obtained as Nujol mulls of the solids, since there is evidence t h a t changes in species occur in solution. For example, in the case of CoC12(NMF)3, the electronic spectrum of the solid, compared with the spectra of [Co(NMF)G]'- and (CoC14)'-, indicates t h a t the solid has the structure [Co(NMF)6][CoCl4]. If the compound is dissolved in N M F , the (CoC14)'- species is attacked by the formamide. I n dilute solution, only Co(NMF);and free chloride ion are present. I n nitromethane, only a tetrahedral species is present, which is not (CoCla)'-. I n addition, the solution is nonconducting. This may be explained by t h e disproportionation:
-
[Co(NMF),j[CoCL]
CH NO
2 [Co(NMF)zClz]+ 2 NMF
Since these complexes are subject to possible solvolysis and rearrangement, depending on the solvent, mull spectra were used for characterization purposes.
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Table IV. Synthetic Procedure Metal Salt"
Step 1
2
Recovery
3
5
4
of Product*
MgCL
20 ml. NMF, stir until dissolved
10 ml. EOF, stir 1 hr.
Triturate 3-4 Add 5 ml. abs. alc., times with 50-ml. stir 10 min. portions of ether
Add 10 ml. ether, stir until obtain fine power
1
MnCL
6 ml. NMF, dissolve
5 ml. EOF, stir 1 hr.
50 ml. ether, stir 1 hr., decant off, repeat
Add 5 ml. abs. alc., stir Yi hr., add 10 ml. ether, stir
1
COClZ
5 ml. NMF, dissolve
5 ml. EOF, stir 1 hr.
Add 50 ml. ether, stir K hr., decant off ether
Add 5 ml. abs. alc., stir 10-15 min.
Scrape solid off walls, crush, and stir until obtain fine powder Add 25 ml. ether, stir overnight
NiCL
20 ml. EOF,
heat, stir 1 hr.
Slowly add 20 ml. NMF, stir vigorously
Initially obtain green gelatinous solid, stir
After 1-2 hr., obtain fine yellow powder
Stir until no trace of green solid remains
cuc12
10 ml. NMF, dissolve
5 ml. EOF, stir 1 hr.
Add 25 ml. ether, stir
Obtain green powder continue stirring 1-2 hr.
ZnC12
5 ml. NMF, dissolve
5 ml. EOF, stir 1 hr.
Add 15 ml. ether, stir overnight
Filter, wash solid with ether, dry in vac.
CdClz
7 ml. NMF, 1 ml. H20, stir % hr.
Obtain thick paste, strong stirring needed
10 ml. EOF, stir 1%hr.
Add 10 ml. abs. alc. stir Overnight
ZnL
1 ml. NMF and 29 ml. ether
Stir overnight
Recrystallize from benzene
"Use 0.01 mole of appropriate hydrated metal salt. *Filter, wash, and dry in vacuum. 1. Wash with mixture of 5 ml. alc. + 10 ml. ether, then with ether. 2. Wash with ether. 3. Wash with benzene, then with ether. 4. Wash with alcohol, then with ether. T h e synthesis of these complexes generally consisted of dissolution of the hydrated metal chloride in N M F and dehydration with ethyl orthoformate @OF), fo1~Owed by the recovery of t h e complex, usually b y addition of ether. The procedures and quantities of reagents used are summarized in Table IV.
LITERATURE CITED (1) Mackay, R. A., Poziomek, E. J., Inorg. Chem. 7 , 1454 (1968). RECEIVED for review July 29, 1968. Accepted December 23, 1968. Elemental analyses performed by the Analytical Research Department, Chemical Research Laboratory, Edgewood Arsenal, Md. 21010.
Synthesis of Hydrazonium Salts PATRICK FOLEY, Jr., ELIZABETH ANDERSON, and FRED DEWEY Harry Diamond Laboratories, Department of the Army, Washington, D. C.
20438
The trimethylhydrazonium iodide, chloride, hexachlorostannate, tosylate, and fluoborate salts of benzaldehyde, 4'-nitrobenzaldehyde, anisaldehyde, and 2',4'-dichlorobenzaldehyde (I) have been prepared and characterized. Similarly, the iodide, chloride, hexachlorostannate, hexafluorophosphate, tetrafluoborate, perchlorate, nitrate, and tosylate bistrimethylhydrazonium salts of glutaraldehyde (11) and trimethylhydrazonium salts of 4-cyano-2,2-dimethylbutyraldehyde (111) have been prepared and characterized. In addition, the bromide and hexafluoroarsenate salts of II are reported. Infrared and NMR data on these compounds are included.
RECENT interest in t h e chemistry of hydrazonium salts ( 5 , 6, 7) prompts this report. As a part of another study, various trimethylhydrazonium salts of benzaldehyde, 4'-nitrobenzaldehyde, anisaldehyde, 2',4'-dichlorobenzaldehyde (I), glutaraldehyde (11), and 4-cyano-2,2-dimethylbutyraldehyde (111) have been prepared by alkylation of t h e corresponding dimethylhydrazones (Figure 1). All of these are new compounds except Ia and IC, p-toluenesulfonates (tosylates), and I b , iodide (7). T h e structures of these compounds were assigned on
272
the basis of their accurate elemental analyses a n d infrared
and nuclear magnetic resonance spectra (Table I). T h e chloride salts did not all analyze correctly because of their hygroscopic nature. Their structures are assigned on t h e basis of spectroscopic evidence (Table I) and t h e fact that they were readily converted to t h e corresponding hexachlorostannates. In t h e infrared, t h e :C = N- absorption was independent of t h e anion, b u t in t h e aromatic salts i t varied with t h e electronegativity of the ring substituent (Table I ) , the more electronegative groups shifting t h e JOURNAL OF CHEMICAL AND ENGINEERING DATA
