Tricarbonyl(methylcyclopentadienyl)manganese

Water solubility

Link to relevant study record(s)

Reference

Endpoint:

water solubility

Type of information:

experimental study

Adequacy of study:

key study

Study period:

No data

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

comparable to guideline study with acceptable restrictions

Qualifier:

equivalent or similar to guideline

Guideline:

EU Method A.6 (Water Solubility)

Principles of method if other than guideline:

Information on the methodology used is described on "Any other information on results incl. tables".

GLP compliance:

no

Remarks:

Study report prior to GLP guidelines

Type of method:

flask method

Key result

Water solubility:

ca. 10 mg/L

Conc. based on:

test mat.

Temp.:

22 °C

Remarks on result:

other: no pH data

Details on results:

See 'any other information on results incl. tables.'

 

Table 1 – mmt content of stirred light-exposed solution

Time, hours	Comments	mmt (mg/l)
		AA	IR
1	Stirred	13
24	Stirred	16
42	Stirred, light exposed	18	11
114	Stirred, light exposed	30	10
162	Stirred, light exposed	36
162	Stirred, light exposed filtered	23
186	Stirred, light exposed	43
186	Stirred, light exposed centrifuged	42
210	Stirred, light exposed	55
210	Stirred, light exposed centrifuged	53
210	Stirred, light exposed filtered	39

Table 2 – mmt of light protected, unstirred solution

Time, hours	Comment	mmt (ppm)
		AA	IR
24	Filtered	11
104		8
104	Filtered	6.5
104	Centrifuged	6.5
200		9	4.6
200	Filtered	7

Table 3 – Loss of mmt from unstirred solutions (concentrations in ppm)

Time, hrs	Saturated		Half-saturated
	AA	IR	AA	IR
0	13.8	8.8	6.8	4.4
24	11.1	6.3	3.8	2.3
96	3.4	2.4	0.9	0.7
120	1.4	1.5	0.5	0.6
192	0.5	<0.4	<0.5	<0.4

 

Table 4 – mmt content of light-protected solution with an excess of mmt

Time, hours	Comments	AA		IR
		Stirred	Unstirred	Stirred	Unstirred
0		5.1	8.8
3.5		39.9	8.5
45		23.2	10.1	15	6
120		21.6	11.2
148		16.4
148	Filtered	14.8	9.8	10
148	Filtered		7.6		5

 

The stirred sample eventually lost all of the excess mmt. The unstirred sample appeared to have lost very little by the time the mmt in the stirred sample disappeared. This indicated the agitation increases the contact between the mmt vapor and air causing a more rapid faster (2x) loss.

 

A similar experiment where the solution was stirred for two hours and allowed to sit for 2 hours was also performed. It was sampled and analysed. It was then allowed to sit for 70 hrs. Samples were again taken and analysed (results in Table 5).

 

Table 5 – mmt content of unstirred solution after initial stirring

Time, hours	mmt (ppm)
	AA	IR
0	7.5	7.5
70	8.7	5.7

Conclusions:

Interpretation of results (migrated information): slightly soluble (0.1-100 mg/L)
The solubility of mmt in water at 22 ºC is 10±2 mg/L.

Executive summary:

The solubility of mmt in water, at room temperature, is 10 ± 2 mg/l. The experiments, conducted to determine the solubility in water demonstrated that mmt is easily lost from water when agitated and stirred. A method was found to maintain the mmt in aqueous solution sufficient to generate a reliable value for its solubility in water. The concentration of mmt was analysed by atomic absorption in order to determine inorganic manganese. If mmt degraded to inorganic Mn, mainly caused by exposure to light, this could lead to an erroneously elevated result. Therefore analysis by IR was used to confirm the concentration of mmt.

Key value for chemical safety assessment

Water solubility:

10 mg/L

at the temperature of:

22 °C