CYANOMOLYMDATES-a colorful family - C&EN Global Enterprise

Nov 6, 2010 - Advertisements that appeared within the print issues of Chem. Eng. News have been included in the C&EN Archives to provide a ...
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a colortul tamilv Cyanomolybdatess.are distinguished for t h e i r : ^BRILLIANT COLORS

^ # STRIKING COLOR CHANGES

SENSITIVITY TO LIGHT

OXIDATION AND REDUCTION POWER Can you exploit the unusual properties of the cyanomolybdate anion sketched above? K , M o ( C N ) 8 is the key compound in this new family. Perhaps the properties of cyanomolybdates described here will lead you to a solution of your research problem.

METAL SALTS Most heavy metal cyanomolybdates a r e insoluble and highly colored. Many metals also form insoluble, colored ammine salts with NH3, N2H4 a n d ethylenediamine. Alkali and alkaline earth salts are generally soluble. ORGANIC SALTS Pyridinium and quinolinium cyanomolybdates form salts, some of which change color with their hydration state. PHOTOSENSITIVITY Under illumination cyanomolybdate solutions change color progressively from yellow t o reddish brown to green or blue. These changes apparently result from successive replacement of u p to four C N by O H . K 4 M O ( O H ) 3 ( C N ) ; V 3 H L > 0 can be isolated from illuminated alkaline solutions.

OXIDATION Permanganate, dilute HNO3 a n d similar reagents oxidize M O I V ( C N ) s ion only to M o v ( C N ) s . This ion is a strong oxidizing agent and is highly sensitive t o light. ALKYLATION Treatment of cyanomolybdate salts with (CH3>2S04 and CH3I converts some of t h e C N groups t o - C N C H 3 and - C H 3 C H C O H with formation of complex methylated compounds. C2H5I acts similarly. HYDROXYCYANIDES Molybdenum also f o r m s compounds of the series: R 4 M o ( C N ) 8 ( O H ) 4 (red) R 3 M o ( C N ) 4 ( O H ) 3 (blue) RUMO(CN)4(OH)2

(purple)

Excess K C N converts these to ïUMoCCN) s.

For more complete data on the properties of cyanomolybdates, write for our new bulletin, "Properties of Cyanomolybdates". Climax Molybdenum Company, Department 2 2 , 500 Fifth Avenue, New York 3 6 , Ν. Υ.

CBLIMAX 14

C&EN

JULY

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MOLYBDENUM

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