# US 5,348,631 A · Method and apparatus for synthesizing lead .beta.-diketonates

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- Number: US 5,348,631 A
- Document ID: US5348631A
- Status: Granted
- Kind: A
- Application number: 08/073,113
- Filed: 1993-06-07
- Granted: 1994-09-20
- Earliest claimed: 1993-06-07
- Assignees: Sharp Kabushiki Kaisha
- Inventors: Seshu B. Desu; May Nyman; Pradyot A. Agaskar
- Web page: https://patentgrep.com/patent/US5348631A

## CPC

- C07C 45/77: Preparation of chelates of aldehydes or ketones
- B01J 19/10: employing sonic or ultrasonic vibrations
- C01G 21/06: Lead monoxide [PbO]
- C07C 49/92: Ketonic chelates
- C01P 2002/82: by IR- or Raman-data
- C01P 2002/86: by NMR- or ESR-data
- C01P 2002/88: by thermal analysis data, e.g. TGA, DTA, DSC
- C01P 2002/89: by mass-spectroscopy
- C01P 2006/34: Melting temperatures
- C07C: ACYCLIC OR CARBOCYCLIC COMPOUNDS
- B01J: CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
- C01G: COMPOUNDS CONTAINING METALS NOT COVERED BY SUBCLASSES C01D OR C01F (metal hydrides {monoborane, diborane or addition complexes thereof} C01B6/00; salts of oxyacids of halogens C01B11/00; peroxides, salts or peroxyacids C01B15/00; thiosulfates, dithionites, polythionates C01B17/64; compounds containing selenium, or tellurium C01B19/00; binary compounds of nitrogen with metals C01B21/06; azides C01B21/08; {compounds containing nitrogen, other non-metals and metal C01B21/082}; metal amides C01B21/092; nitrites C01B21/50; {compounds of noble gases C01B23/0005}; phosphides C01B25/08; salts of oxyacids of phosphorus C01B25/16; carbides C01B32/90; compounds containing silicon C01B33/00; compounds containing boron C01B35/00; compounds having molecular sieve properties but not having base-exchange properties C01B37/00; compounds having molecular sieve and base-exchange properties, e.g. crystalline zeolites, C01B39/00; cyanides C01C3/08; salts of cyanamide C01C3/16; thiocyanates C01C3/20)
- C01P: INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS

## Abstract

A method and apparatus for the synthesis of .beta.-diketonates such as Pb(fod).sub.2 and Pb(thd).sub.2 for use as precursors in metalorganic chemical vapor deposition processes. Lead oxide and a medium of pentane and a protonated ligand (H-fod or H-thd) are combined in a flask and subjected to reaction-promoting ultrasonic waves. The flask is immersed in a water bath to maintain a constant cool temperature, and the flask may include one or more arms for cooling and circulation of the medium during the reaction.

## Claims

### Claim 1

A method of producing a lead .beta.-diketonate, comprising: combining lead oxide with a medium; subjecting the combined lead oxide and medium to ultrasonic waves, and recovering said lead .beta.-diketonate.

### Claim 2 (depends on 1)

The method of claim 1, further comprising: heating the medium in a vacuum to vaporize non-.beta.-diketonate compounds in the medium.

### Claim 3 (depends on 1)

The method of claim 1, wherein the lead oxide and medium are combined in a flask, and the step of subjecting the combined lead oxide and medium to ultrasonic waves is by placing an ultrasonic probe into the flask.

### Claim 4 (depends on 3)

The method of claim 3, wherein the flask has a lower portion and an upper portion above the lower portion, and at least one conduit having one end in communication with the lower portion and another end in communication with the upper portion, and further comprising circulating the combined lead oxide and medium through the conduit while subjecting the combined lead oxide and medium to ultrasonic waves.

### Claim 5 (depends on 4)

The method of claim 4, wherein the flask is immersed in a water bath, and further comprising cooling the conduit and thereby cooling the combined lead oxide and medium with the water bath while subjecting the combined lead oxide and medium to ultrasonic waves.

### Claim 6 (depends on 5)

The method of claim 5, wherein the water bath is contained in a container, and further comprising flowing water through the container while subjecting the combined lead oxide and medium to ultrasonic waves.

### Claim 7 (depends on 4)

The method of claim 4, wherein the circulation of the combined lead oxide and medium through the conduit is from the end in communication with the lower portion to the end in communication with the upper portion.

### Claim 8 (depends on 1)

The method of claim 1, wherein the .beta.-diketonate includes Pb(fod).sub.2 and the medium includes H-fod.

### Claim 9 (depends on 1)

the method of claim 1, wherein the .beta.-diketonate includes Pb(thd).sub.2 and the medium includes H-thd.

### Claim 10 (depends on 1)

The method of claim 1, wherein the medium includes pentane.