Complex Compounds of Ethylquinolinium Bromide with Salts of Certain Metals
Abstract Generated abstract
This paper investigates the formation of complex compounds between ethylquinolinium bromide and halide salts of selected metals, a class described as comparatively little studied beyond hydrohalide complexes of quinoline derivatives. The author prepares the compounds by mixing hot aqueous solutions of the components, followed by precipitation or crystallization, recrystallization, and analytical determination of metal, halogen, and water content. Fifteen crystalline complexes are reported, mainly of the types R2MeX4 and RMeX4, with measured colors, melting points, solubilities, and analytical compositions. The study also discusses dissociation behavior in solution, color changes attributed to complex anions, rhodanide substitution in several cases, and proposes an electron-theory structural scheme for the complexes.
Full Text
Complex Compounds of Ethylquinolinium Bromide with Salts of Certain Metals
I. I. Molodykh
On reviewing the literature data on complexes of quinoline derivatives, it is easy to become convinced that only complexes with hydrohalic salts [1, 4, 5, 10, 11] have been well studied. As regards complexes of its other derivatives, then, apart from a few salts of quinolinemethylate and ethylate with $\mathrm{PtCl}_4$ and $\mathrm{AuCl}_3$, quinoline bromo- (iodo-) ethylate with $\mathrm{Hg(CN)_2}$ [2], and compounds obtained by Prof. Ya. I. Mikhailenko and his coworkers (“Complex compounds of benzylquinolinium chloride with salts of metals”) [7], we have here a very large unexplored field.
In my experimental work I have dealt with the preparation of complex compounds of the halides of certain metals with ethylquinolinium bromide, for which, as indicated above, a salt with mercuric cyanide had been obtained.
The starting product, ethylquinolinium bromide $\mathrm{C_9H_7NC_2H_5Br \cdot H_2O}$, was first obtained and described in 1883 [3]. The combination of both freshly distilled components proceeds readily even in the cold. The salt crystallizes from water or alcohol in large rhombic crystals, which melt at $80^\circ$ and at $100^\circ$ lose water. Ethylquinolinium bromide is readily soluble in water, alcohol, and chloroform, but not in ether.
The structural formula of this compound may be represented on the basis of the analogy of quinoline bromoethylate with ammonium bromide. According to Werner’s views, the ammonium group has a complex structure. Applying Lewis’s ideas to the process of formation of the $\mathrm{NH_4^+}$ ion, the following scheme is obtained for the reaction between $\mathrm{NH_3}$ and $\mathrm{HBr}$:
\[ \begin{array}{c} \ \ \mathrm{H}\\[-2pt] \ \ \ddot{}\\[-2pt] \mathrm{H}:\mathrm{N}: + \mathrm{H}:\mathrm{Br} = \left[ \begin{array}{c} \ \ \mathrm{H}\\[-2pt] \ \ \ddot{}\\[-2pt] \mathrm{H}:\mathrm{N}:\mathrm{H}\\[-2pt] \ \ \ddot{}\\[-2pt] \ \ \mathrm{H} \end{array} \right]^+ \left[ \begin{array}{c} \ddot{}\\[-2pt] :\mathrm{Br}:\\[-2pt] \ddot{} \end{array} \right]^- \\[-2pt] \mathrm{H} \end{array} \]
The strongly negatively polarized nitrogen atom draws toward itself the hydrogen ion from bromine. In contrast to ordinary chemical reactions that lead to the formation of valence bonds, the process under consideration is not accompanied by the formation of new electron pairs. It is based on the electrostatic attraction of the hydrogen ion, on the one hand by the nitrogen of ammonia, and on the other by the bromine ion. Compounds formed by the drawing together of constituent parts, not connected with the appearance of new electron pairs, are called complex compounds. Ethylquinolinium may be regarded as a tetrasubstituted ammonium, three hydrogens of which are replaced by the trivalent group $\mathrm{C_9H_7^{\cdots}}$, and the fourth hydrogen, attached by means of the pair of electrons of nitrogen, by the ethyl radical. Pri-
Taking into account all the foregoing, for ethylquinolinium bromide we shall have the following structural formula:
\[ \left[ \begin{array}{c} \text{quinoline nucleus}\\[-2pt] \mathrm{N{:}C_2H_5} \end{array} \right] \left[:\mathrm{Br}:\right] \]
True, regarding the structure of compounds of this kind there also exists another opinion. Grant [6], in a number of his works, advances the idea that the hydrocarbon radical is added to the nitrogen of pyridine or quinoline, while the chlorine attaches to the neighboring \((\alpha)\) carbon or to the carbon standing opposite the nitrogen \((\gamma)\).
\[ \text{quinoline} + \mathrm{CH_3X} = \text{\(N\)-methylquinoline with \(X\) at the adjacent carbon} \quad \text{or} \quad \text{\(N\)-methylquinoline with \(X\) at the opposite carbon} \]
Such a structure is contradicted by the existence of such tetra-substituted ammoniums as \([\mathrm{N(C_2H_5)_4}] \mathrm{Cl}\), all the radicals of which have saturated chains of carbon atoms.
Heterocyclic amines, as well as salts of tetra-substituted ammoniums, as the literature data have shown, readily form with salts of heavy metals compounds which, by their properties, may with equal right be assigned both to complexes and to double salts. The substances obtained by me, \((\mathrm{C_9H_7NC_2H_5})_2\mathrm{CuBr_4}\), \(\mathrm{C_9H_7NC_2H_5FeCl_3Br}\), and a number of others, are compounds of the type \(\mathrm{R'_2MeX_4''}\) and \(\mathrm{R'MeX'_4}\), where \(R\) will be \((\mathrm{C_9H_7NC_2H_5})\); and the anion is formed by an ion of a heavy metal with four monovalent halogen ions, i.e. \(\mathrm{MeX''_4}\) or \(\mathrm{MeX'_4}\).
For the complexes obtained we have a large dissociation energy of the molecules of the substances taken into ions, and only slightly exceeding it in magnitude is the sum of the energies of formation of the complex anion \(\mathrm{MeX''_4}\) and of the molecules of the complex itself \(\mathrm{R_2MeX_4}\) [9]. This may be judged from the behavior of the substance in solution, which is especially clearly seen in the presence of colored ions. Thus, the blue color of concentrated solutions of the complex \((\mathrm{C_9H_7NC_2H_5})_2\mathrm{CoCl_2Br_2}\) depends on the presence of the blue anion \((\mathrm{CoCl_2Br_2})''\), appearing as a result of the electrolytic dissociation of the substance:
\[ [\mathrm{C_9H_7NC_2H_5}]_2\mathrm{CoCl_2Br_2} \rightleftarrows 2[\mathrm{C_9H_7NC_2H_5}]' + (\mathrm{CoCl_2Br_2})''. \]
Upon subsequent dilution of the solution, the complex anion \([\mathrm{CoCl_2Br_2}]''\) dissociates further according to the equation: \((\mathrm{CoCl_2Br_2})'' \rightleftarrows \mathrm{Co} + 2\mathrm{Cl'} + 2\mathrm{Br'}\), which causes the blue color to change to pink, belonging to the cobalt ion. The phenomenon of a change in color upon dilution of the solution can be observed in all cases where colored ions are present. This circumstance makes it possible, without difficulty, to determine the composition of the substances obtained.
On the other hand, it is known that an aqueous solution of cobalt chloride of red color turns blue upon addition of concentrated HCl or concentrated solutions of alkali and alkaline-earth chlorides. No one has devoted more attention to explaining these sharp color changes than Donnan and Basset, who, on the basis of physico-
chemical data obtained by them in studying this phenomenon, came to the conclusion that the blue color must belong to the complex ions \(\mathrm{CoCl_4''}\) and \(\mathrm{CoCl'_3}\). The correctness of their theory was confirmed by the experiments of Percival and Wardlaw on the molecular conductivity of alcoholic solutions of the salts they obtained: \((\mathrm{C_9H_7NH})'_2\mathrm{CoCl''_4}\), \((\mathrm{C_5H_5NH})_2\mathrm{CoCl_4}\), etc. [10]. Thus, in the newly obtained compounds, on the basis of the considerations given above, both the cation and the anion are complex. Their structure may be represented as follows:
\[ \begin{array}{c} \text{[structural formula of ethylquinolinium complex cation with } \mathrm{X:Me:X} \text{ and } \mathrm{X}\text{]} \qquad \text{[structural formula of ethylquinolinium complex anion with } \mathrm{X:Me:X} \text{ and } \mathrm{X}\text{]} \end{array} \]
Experimental Part
All salts were taken chemically pure. The solutions were prepared immediately before the experiment. The complexes were obtained by mixing hot aqueous (sometimes acidified to avoid hydrolysis) solutions of the components. If a precipitate formed, it was filtered off on a Büchner funnel, washed with alcohol, and dried in a desiccator. In the absence of a precipitate, the mixture was evaporated on a water bath until crystallization began and then cooled. For purification, the product obtained was recrystallized repeatedly. The air-dry substance was subjected to determination of crystallization water, after which analysis for metal and halogen followed. To avoid the influence of the organic part of the molecule, the metal was determined in most cases as the sulfide or in the free state; the halogens, by volumetric and gravimetric methods. Melting temperatures were determined in capillaries.
With ethylquinolinium bromide and salts of various metals, 15 complex compounds were obtained. The results are placed in the following table:
Table 1
| No. | Formula of the complex | Color | Melting temp. | Relative solubility in water |
|---|---|---|---|---|
| 1 | \((\mathrm{C_9H_7NC_2H_5})_2\mathrm{CuCl_2Br_2}\) | Brown | 142 | Readily soluble |
| 2 | \((\mathrm{C_9H_7NC_2H_5})_2\mathrm{CuBr_4}\) | Black | 161 | Readily soluble |
| 3 | \(\mathrm{C_9H_7NC_2H_5AuCl_3Br}\) | Orange | 172.5 | Sparingly soluble |
| 4 | \((\mathrm{C_9H_7NC_2H_5})_2\mathrm{ZnCl_2Br_2}\) | White | 187.5 | Readily soluble |
| 5 | \((\mathrm{C_9H_7NC_2H_5})_2\mathrm{CdCl_2Br_2}\) | White | 227.5 | Slightly soluble |
| 6 | \((\mathrm{C_9H_7NC_2H_5})_2\mathrm{CdJ_2Br_2}\) | Yellowish | 163.5 | Slightly soluble |
| 7 | \((\mathrm{C_9H_7NC_2H_5})_2\mathrm{HgCl_2Br_2}\) | White | 180 | Slightly soluble |
| 8 | \((\mathrm{C_9H_7NC_2H_5})_2\mathrm{SnCl_2Br_2}\) | Yellowish | 285 | Slightly soluble |
| 9 | \((\mathrm{C_9H_7NC_2H_5})_2\mathrm{PbBr_4}\) | Light yellow | 230 | Slightly soluble |
| 10 | \(\mathrm{C_9H_7NC_2H_5AsCl_3Br}\) | White | 148.5 | Readily soluble |
| 11 | \(\mathrm{C_9H_7NC_2H_5SbCl_3Br}\) | White | 147 | Slightly soluble |
| 12 | \(\mathrm{C_9H_7NC_2H_5BiCl_3Br}\) | White | 257 | Sparingly soluble |
| 13 | \((\mathrm{C_9H_7NC_2H_5})_2\mathrm{MnCl_2Br_2}\) | Waxy yellow | 177.5 | Readily soluble |
| 14 | \(\mathrm{C_9H_7NC_2H_5FeCl_3Br \cdot H_2O}\) | Light brown | 62.5 | Readily soluble |
| 15 | \((\mathrm{C_9H_7NC_2H_5})_2\mathrm{CoCl_2Br_2}\) | Blue | 164.5 | Readily soluble |
Complex \((\mathrm{C}_9\mathrm{H}_7\mathrm{NC}_2\mathrm{H}_5)_2\mathrm{CuCl}_2\mathrm{Br}_2\) is obtained by mixing concentrated solutions of the components, taking one molecule of \(\mathrm{CuCl}_2\) per 2 molecules of ethylquinolinium bromide. The solution was evaporated on a water bath until crystallization began. On cooling, small, brown crystals with a red tint, lustrous in appearance, separated; these were removed from the mother liquor and pressed through filter paper. The complex dissolves readily in water and alcohol and is insoluble in ether. On dissolution there is first formed a dark-brown solution with a greenish tint, which on dilution becomes blue. The difference in color is readily explained by the fact that the initially formed dark-brown ions \((\mathrm{CuCl}_2\mathrm{Br}_2)''\), on dilution of the solution, dissociate with formation of the blue copper ion, which accounts for the change in color. M.p. \(149^\circ\).
Analysis of the complex
| Determination of copper (as \(\mathrm{Cu}_2\mathrm{S}\)) |
Determination of chlorine and bromine (gravimetric method) |
|---|---|
| Sample 0.5095 g. | Sample 0.1052 g. |
| \(\mathrm{Cu}_2\mathrm{S}\) 0.0664 g. | \(\mathrm{AgCl}+\mathrm{AgBr}\) 0.1141 g. |
| Cu 0.0530 g. | \(\mathrm{AgCl}\) 0.0988 g. |
| Cu 10.4% | \(\mathrm{AgBr}\) 0.0647 g; Br 0.02753 g. |
| \(\mathrm{AgCl}\) 0.0494 g; Cl 0.01222 g. |
For \((\mathrm{C}_9\mathrm{H}_7\mathrm{NC}_2\mathrm{H}_5)_2\mathrm{CuCl}_2\mathrm{Br}_2\), calculated in %: Cu 10.41; Cl 11.61; Br 26.24;
found in %%: Cu 10.4; Cl 11.6; Br 26.7.
Complex \((\mathrm{C}_9\mathrm{H}_7\mathrm{NC}_2\mathrm{H}_5)_2\mathrm{CuBr}_4\) is formed by mixing concentrated solutions of the components and subsequently evaporating on a water bath until black films appear on the surface. On cooling the solution, numerous small, black crystals with a gray sheen, lustrous in appearance, separate. M.p. \(161^\circ\). Like the preceding compound, it is readily soluble in water and alcohol and insoluble in ether.
Analysis of the complex
| Determination of copper (as \(\mathrm{Cu}_2\mathrm{S}\)) |
Determination of bromine (as \(\mathrm{AgBr}\)) |
|---|---|
| Sample 0.2348 g. | Sample 0.1400 g. |
| \(\mathrm{Cu}_2\mathrm{S}\) 0.02665 g. | \(\mathrm{AgBr}\) 0.1515 g. |
| Cu 0.02127 g. | Br 0.06445 g. |
For \((\mathrm{C}_9\mathrm{H}_7\mathrm{NC}_2\mathrm{H}_5)_2\mathrm{CuBr}_4\), calculated in %: Cu 9.09; Br 45.71;
found in %: Cu 9.057; Br 46.04.
Complex \(\mathrm{C}_9\mathrm{H}_7\mathrm{NC}_2\mathrm{H}_5\mathrm{AuCl}_3\mathrm{Br}\) is obtained by mixing a concentrated solution of ethylquinolinium bromide with a dilute solution of chloroauric acid. A bright-orange amorphous precipitate separates; on standing it turns finely crystalline and darker in color. The complex is noticeably insoluble both in water and in alcohol. For analysis it was dissolved in nitric acid. M.p. \(171\text{—}172^\circ\). On melting it becomes dark red.
Analysis of the complex
| Determination of gold (as metal) |
Determination of chlorine and bromine (gravimetric method) |
|---|---|
| Sample 0.1278 g. Au 0.0464 g. 36.29% |
Sample 0.1356 g. AgCl + AgBr 0.1546 g. AgCl 0.1439 g. AgBr 0.0472 g. Br 0.02006 g. AgCl 0.1074 g. Cl 0.02658 g. |
For \( \mathrm{C_9H_7NC_2H_5AuCl_3Br} \), calculated in %: Au 36.41; Cl 19.66; Br 14.75.
Found in %: Au 36.29; Cl 19.64; Br 14.79.
The complex \( (\mathrm{C_9H_7NC_2H_5})_2\mathrm{ZnCl_2Br_2} \) separates on mixing solutions of the components in the form of small white crystals with a strong mother-of-pearl luster. After some time the crystals acquire a pale-pink tint. It is sparingly soluble in cold water and alcohol, readily soluble in hot water. M.p. 188.5°.
Analysis of the complex
| Determination of zinc | Determination of chlorine and bromine |
|---|---|
| Sample 0.4832 g. ZnO 0.0620 g. Zn 0.0498 g. In % Zn 10.3. |
Sample 0.2514 g. AgCl + AgBr 0.2715 g. AgCl 0.2351 g. AgBr 0.1540 g. Br 0.06552 g. AgCl 0.1175 g. Cl 0.02907 g. |
For \( (\mathrm{C_9H_7NC_2H_5})_2\mathrm{ZnCl_2Br_2} \), calculated in %: Zn 10.68; Cl 11.58; Br 26.1.
Found in %: Zn 10.3; Cl 11.56; Br 26.06.
The complex \( (\mathrm{C_9H_7NC_2H_5})_2\mathrm{CdCl_2Br_2} \) separates immediately on mixing hot or cold solutions of the components in the form of a finely crystalline powdery precipitate. The precipitate, filtered on a Büchner funnel and washed with alcohol, was dried in a desiccator over sulfuric acid. M.p. 227.5°. It is sparingly soluble in water and alcohol. It dissolves in dilute acids. The complex is white.
Analysis of the complex
| Determination of cadmium (as \( \mathrm{CdSO_4} \)) |
Determination of chlorine and bromine |
|---|---|
| Sample 0.2168 g. \(\mathrm{CdSO_4}\) 0.0688 g. Cd 0.03708 g. In % 17.1 Cd. |
Sample 0.2452 g. AgCl + AgBr 0.2476 g. AgCl 0.2145 g. AgBr 0.1395 g. Br 0.05934 g. AgCl 0.1081; Cl 0.02673 g. |
For \( (\mathrm{C_9H_7NC_2H_5})_2\mathrm{CdCl_2Br_2} \), calculated in %: Cd 17.05; Cl 10.92; Br 24.24.
Found in %: Cd 17.1; Cl 10.9; Br 24.2.
The complex \((\mathrm{C}_9\mathrm{H}_7\mathrm{NC}_2\mathrm{H}_5)_2\mathrm{CdJ}_2\mathrm{Br}_2\) precipitates in the form of a yellowish-white finely crystalline precipitate when solutions of the components are mixed. After filtration the precipitate was washed with alcohol and dried in a desiccator over sulfuric acid. It is sparingly soluble in water and alcohol, but dissolves in dilute acids. M.p. \(163.5^\circ\).
Analysis of the complex
| Determination of cadmium | Determination of iodine and bromine |
|---|---|
| Sample \(0.3546\) g. | Sample \(0.2621\) g. |
| \(\mathrm{CdSO}_4\) \(0.0885\) g. | \(\mathrm{AgJ}+\mathrm{AgBr}\) \(0.2631\) g. |
| \(\mathrm{Cd}\) \(0.0477\) g. | \(\mathrm{AgCl}\) \(0.1784\) g. |
| \(\mathrm{Cd}\) \(13.45\%\). | \(\mathrm{AgJ}\) \(0.1454\) g.; \(\mathrm{J}\) \(0.07859\) g. |
| \(\mathrm{AgBr}\) \(0.1177\) g. | |
| \(\mathrm{Br}\) \(0.05008\) g. |
For \((\mathrm{C}_9\mathrm{H}_7\mathrm{NC}_2\mathrm{H}_5)_2\mathrm{CdJ}_2\mathrm{Br}_2\), calculated in %: \(\mathrm{Cd}\) 13.35; \(\mathrm{Br}\) 18.98; \(\mathrm{J}\) 30.14.
Found in %: \(\mathrm{Cd}\) 13.45; \(\mathrm{Br}\) 19.11; \(\mathrm{J}\) 29.98.
The complex \((\mathrm{C}_9\mathrm{H}_7\mathrm{NC}_2\mathrm{H}_5)_2\mathrm{HgCl}_2\mathrm{Br}_2\) separates as a white powdery precipitate when solutions of ethylquinolinium bromide and mercuric chloride are poured together. The complex is somewhat soluble in water and in doing so dissociates into its constituent components, as may be judged from the red precipitate of \(\mathrm{HgJ}_2\) formed on addition of potassium iodide. On standing, the red color of the precipitate disappears and the complex becomes light yellow. Evidently, a reaction of exchange of the halogens of the complex for iodine takes place:
\[ (\mathrm{C}_9\mathrm{H}_7\mathrm{NC}_2\mathrm{H}_5)_2\mathrm{HgCl}_2\mathrm{Br}_2 + 4\mathrm{KJ} = (\mathrm{C}_9\mathrm{H}_7\mathrm{NC}_2\mathrm{H}_5)_2\mathrm{HgJ}_4 + 2\mathrm{KBr} + 2\mathrm{KJ}, \]
and the salt formed in this process is less soluble in water. M.p. \(180^\circ\).
Analysis of the complex
| Determination of mercury (as HgS) |
Determination of bromine and chlorine |
|---|---|
| Sample \(0.2482\) g. | Sample \(0.1938\) g. |
| \(\mathrm{HgS}\) \(0.0773\) g. | \(\mathrm{AgCl}+\mathrm{AgBr}\) \(0.1721\) g. |
| \(\mathrm{Hg}\) \(0.06664\) g. | \(\mathrm{AgCl}\) \(0.1490\) g. |
| \(\mathrm{AgBr}\) \(0.0975\) g. | |
| \(\mathrm{Br}\) \(0.0415\) g. | |
| \(\mathrm{AgCl}\) \(0.0746\) g. | |
| \(\mathrm{Cl}\) \(0.01845\) g. |
For \((\mathrm{C}_9\mathrm{H}_7\mathrm{NC}_2\mathrm{H}_5)_2\mathrm{HgCl}_2\mathrm{Br}_2\), calculated in %: \(\mathrm{Hg}\) 26.83; \(\mathrm{Cl}\) 9.49; \(\mathrm{Br}\) 21.39.
Found in %: \(\mathrm{Hg}\) 26.86; \(\mathrm{Cl}\) 9.52; \(\mathrm{Br}\) 21.41.
The complex \((\mathrm{C}_9\mathrm{H}_7\mathrm{NC}_2\mathrm{H}_5)_2\mathrm{SnCl}_2\mathrm{Br}_2\) is formed as a yellowish-white, poorly crystallizing precipitate when an aqueous solution of ethylquinolinium bromide and a freshly prepared hydrochloric-acid solution of stannous chloride are mixed. The complex is sparingly soluble in water and alcohol. It dissolves in dilute acids. M.p. \(285^\circ\); on melting it blackens.
Analysis of the complex
| Determination of tin (as SnO₂) |
Determination of chlorine and bromine |
|---|---|
| Sample 0.2822 g. SnO₂ 0.0641 g. Sn 0.05052 g. Sn 17.9%. |
Sample 0.2564 g. AgCl + AgBr 0.2553 g. AgCl 0.2212 g. AgBr 0.1444 g. Br 0.06144 g. AgCl 0.1109 g. Cl 0.02744 g. |
For $(\mathrm{C_9H_7NC_2H_5})_2\mathrm{SnCl_2Br_2}$ calculated in %: Sn 17.86; Cl 10.65; Br 24.00;
found in %: Sn 17.90; Cl 10.7; Br 23.96.
Complex $(\mathrm{C_9H_7NC_2H_5})_2\mathrm{PbBr_4}$ separates in the form of small, lustrous needles of yellowish-white color. The complex is only slightly soluble in water, even on boiling. It is soluble in dilute nitric acid. M.p. 230°.
Analysis of the complex
| Determination of lead | Determination of bromine |
|---|---|
| Sample 0.2834 g. PbSO₄ 0.1021 g. Pb 0.06976 g. Pb 24.61%. |
Sample 0.0993 g. AgBr 0.0886 g. Br 0.0377 g. Br 37.96%. |
For $(\mathrm{C_9H_7NC_2H_5})_2\mathrm{PbBr_4}$ calculated in %: Pb 24.57; Br 37.92;
found in %: Pb 24.61; Br 37.96.
Complex $\mathrm{C_9H_7NC_2H_5AsCl_3Br}$ is formed after strong evaporation of a mixture of alcoholic solutions of the components, acidified with HCl, in the form of white, small, lustrous crystals. M.p. 148.5°.
Analysis of the complex
| Determination of arsenic | Determination of chlorine and bromine |
|---|---|
| Sample 0.2486 g. As₂S₃ 0.0726 g. As 0.0442 g. As 17.78%. |
Sample 0.1926 g. AgCl + AgBr 0.2836 g. AgCl 0.2730 g. AgBr 0.08604. Br 0.03661 g. AgCl 0.1976. Cl 0.04889 g. |
For $\mathrm{C_9H_7NC_2H_5AsCl_3Br}$ calculated in %: As 17.86; Cl 25.37; Br 19.05;
found in %: As 17.78; Cl 25.39; Br 19.01.
Complex $\mathrm{C_9H_7NC_2H_5SbCl_3Br}$ is obtained by mixing an aqueous solution of ethylquinolinium bromide with a freshly prepared hydrochloric-acid solution of antimony chloride. A white powdery precipitate immediately separates, which was filtered off, washed with alcohol, and dried in a desiccator. In the moist state the precipitate becomes slightly pink, especially at the edges. It is only slightly soluble in water and alcohol. It dissolves readily in fairly concentrated acid. M.p. 147°. On melting it first turns yellow and softens, and with a further rise in temperature gives an amber-colored liquid.
Analysis of the complex
Determination of antimony
Sample 0.2588 g.
Sb₂S₃ 0.0946 g.
Sb 0.0678 g.
Sb 26.19%.
Determination of chlorine and bromine
Sample 0.1898 g.
AgCl + AgBr 0.2514 g.
AgCl 0.2333 g.
AgBr 0.0766 g; Br 0.0326 g.
AgCl 0.1748 g; Cl 0.04314 g.
Br 17.18%; Cl 22.79%.
For C₉H₇NC₂H₅SbCl₃Br calculated in %: Sb 26.11; Cl 22.81; Br 17.14.
Found in %: Sb 26.19; Cl 22.79; Br 17.18.
The complex C₉H₇NC₂H₅BiCl₃Br precipitates in the form of a white, powdery, fairly heavy precipitate when a hydrochloric-acid solution of bismuth chloride is added to an aqueous solution of ethylquinolinium bromide. The precipitate is sparingly soluble even in heated water. It dissolves in dilute acids when the temperature is raised. M.p. 257°. On melting it turns yellow. The moist salt acquires a slightly pinkish color, which remains after it is dried.
Analysis of the complex
Determination of bismuth
Sample 0.2733 g.
Bi₂S₃ 0.1270 g.
Bi 0.1031 g.
Bi 37.75%.
Determination of chlorine and bromine
Sample 0.1664 g.
AgCl + AgBr 0.1864 g.
AgCl 0.1730 g.
AgBr 0.0566 g; Br 0.02409 g.
AgCl 0.1298 g; Cl 0.03199 g.
Cl 19.2%; Br 14.6%.
Calculated in %: Bi 37.78; Cl 19.23; Br 14.44.
Found in %: Bi 37.75; Cl 19.2; Br 14.6.
The complex (C₉H₇NC₂H₅)₂MnCl₂Br₂. Concentrated solutions of the components are mixed together, and the mixture is evaporated to a very small volume. After cooling, the resulting syrup-like liquid separates out shiny, light-waxy-yellow small crystals of the complex. The salt is extremely readily soluble in water, alcohol, and dilute acids, but on addition of potassium rhodanide a white crystalline precipitate falls. Evidently, in the complex, replacement of halogen by rhodanide has occurred, as a result of which its solubility sharply decreased. M.p. 177.5°.
Analysis of the complex
Determination of manganese
Sample 0.2346 g.
Mn₃O₄ 0.0298 g.
Mn 0.02146 g.
Mn 9.15%.
Determination of bromine and chlorine
Sample 0.1820 g.
AgCl + AgBr 0.2006 g, converted
to AgCl 0.01737 g.
AgBr 0.1138 g; Br 0.04842 g.
AgCl 0.08684 g; Cl 0.02148 g.
Cl 11.81%; Br 26.6%.
For (C₉H₇NC₂H₅)₂MnCl₂Br₂ calculated in %: Mn 9.12; Cl 11.79; Br 25.56.
Found in %: Mn 9.15; Cl 11.81; Br 26.60.
Complex \(C_9H_7NC_2H_5FeCl_3Br \cdot H_2O\). Concentrated solutions of the components were mixed together, and the mixture was strongly evaporated on a water bath. After cooling, well-formed, small, light-brown crystals with a yellowish tint separate from the thick solution. The complex is highly soluble in water and alcohol. It is slightly hygroscopic. M.p. \(62.5^\circ\). On treatment with potassium rhodanide, a purple precipitate separates. Apparently, substitution of the halogen of the complex by rhodanide occurs, as a result of which its solubility decreases.
Analysis of the complex
Determination of crystallization water
Sample \(0.5248\) g. Loss on heating to \(110^\circ\)—\(0.0221\) g.
Calculated \(H_2O\) \(4.3\%\).
Found \(H_2O\) \(4.21\%\).
Further, I analyze the dehydrated salt.
| Determination of iron | Determination of chlorine and bromine |
|---|---|
| Sample \(0.2651\) g. \(Fe_2O_3\) \(0.0528\) g. \(Fe\) \(0.0369\) g. \(Fe\) \(13.90\%\). |
Sample \(0.2875\) g. \(AgCl + AgBr\) \(0.4438\) g, converted to \(AgCl\) \(0.4120\) g. \(AgBr\) \(0.1346\) g; \(Br\) \(0.05728\) g. \(AgCl\) \(0.3092\) g; \(Cl\) \(0.0765\) g. \(Cl\) \(26.6\%\); \(Br\) \(19.92\%\). |
For \(C_9H_7NC_2H_5FeCl_3Br\) calculated, in %: \(Fe\) \(13.94\); \(Cl\) \(26.64\); \(Br\) \(19.96\).
Found, in %: \(Fe\) \(13.90\); \(Cl\) \(26.60\); \(Br\) \(19.92\).
Complex \((C_9H_7NC_2H_5)_2CoCl_2Br_2\) is obtained on cooling the solution of the mixture of components evaporated on a water bath, in the form of lustrous, cornflower-blue, well-formed, small crystals. After their separation, the initially blue solution becomes pink. The complex is highly soluble in water and in alcohol. M.p. \(164^\circ\). On adding potassium rhodanide to an aqueous solution of the obtained complex, a bright-blue crystalline precipitate falls out. Probably, substitution of the halogen by rhodanide occurs, whence the decrease in solubility.
Analysis of the complex
| Determination of cobalt | Determination of chlorine and bromine |
|---|---|
| Sample \(0.3542\) g. \(Co\) \(0.0346\) g. \(Co\) \(9.77\%\). |
Sample \(0.2382\) g. \(AgCl + AgBr\) \(0.2601\) g, converted to \(AgCl\) \(0.2251\) g. \(AgBr\) \(0.1479\) g; \(Br\) \(0.06292\) g. \(AgCl\) \(0.1122\) g; \(Cl\) \(0.02776\) g. \(Cl\) \(11.65\%\). \(Br\) \(26.41\%\). |
For \((C_9H_7NC_2H_5)_2CoCl_2Br_2\) calculated, in %: \(Co\) \(9.73\); \(Cl\) \(11.69\); \(Br\) \(26.38\).
Found, in %: \(Co\) \(9.77\); \(Cl\) \(11.65\); \(Br\) \(26.41\).
It should be noted that ethylquinolinium bromide does not combine with sulfate, nitrate, or carbonate salts of metals. Under the above conditions, it was not possible to obtain compounds of ethylquinolinium bromide with mineral salts in other stoichiometric ratios.
Conclusions
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Ternary complexes of the halides of certain metals with ethylquinolinium bromide, of composition \(R_2MeX_4\) and \(RMeX_4\), have been obtained and studied.
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Among the complex compounds obtained, the salts of ethylquinolinium bromide with auric chloride and bismuth chloride proved to be sparingly soluble. The others dissolve in water and alcohol and are insoluble in ether.
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Under the action of water, the complexes obtained dissociate into their constituent components and, upon crystallization from the resulting solution, separate again.
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The complexes of ethylquinolinium bromide with manganous chloride, ferric chloride, and cobaltous chloride decrease their solubility when the halogen is replaced by rhodanide.
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The complexes are crystalline substances stable in the dry state, with melting points from 62.5 to 285°.
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A structural scheme for the complexes obtained is proposed, based on the electron theory.
Literature
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- Grossmann H. u. Hunseler F.—Zeit. f. anorg. Chem. Vol. 46, 376. 1905.
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- Nekrasov B. V.—Course of General Chemistry, Vol. 1, p. 313, 1935. M.—L.
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