Glassware, handling/storing

All reagents were stored and handled only under anhydrous conditions in a dry box. Glassware was dried at 175 °C. and cooled in the dry box. Standard solutions were prepared by weight, and all solvent and solutions were filtered before use. 

The extreme sensitivity of RNA to the ubiquitous inter- and intracellular nudeases (for example on the skin of the investigator) makes special precautions necessary for effective RNA preparations. The use of disposable containers is recommended, or glassware that has been soaked in dilute hydrochloric acid and rinsed with autoclaved distilled water. Disposable gloves must be worn in all procedures where RNA is handled, or is likely to come into contact with RNA, such as solutions, chemicals, glassware, spatulas etc. Buffers for RNA work should be prepared from reagents reserved for this purpose, and stored separately. Buffers can be treated with 0.2 % (v/v) diethylpyrocarbonate (care - this is carcinogenic) and autodaved to inactivate RNases, or at least those with adive site histidines. Since most nucleases require Mg2 for activity, the addition of EDTA in mM concentrations to solutions is also recommended. 

Ni(cod)2 is an air-sensitive complex requiring some care in handling. The yellow crystalline material (used as purchased, without further purification) is transferred in a glovebag under N, or in Schlenk-type glassware. Preparation of a stock solution of Ni(cod)2 (ca. 0.1 M in toluene) is convenient for small-scale reactions. This yellow solution can be stored in a freezer for at least 2 months with only slight deposition of a black precipitate. 

Iodogermane is very similar to the chloro derivative but is less volatile and has a higher melting point (m.p. — 15° extrapolated b.p. ca. 90° v.p. at 0°, 20 torr). It is rather less stable at room temperature than chlorogermane and is best handled in clean glassware with subdued lighting. It should be stored at — 196°. 

Digermylcarbodiimide is a rather involatile liquid, having a vapor pressure of about 2 torr at 20°.3 The compound decomposes slowly above 0° and must be stored at low temperatures, preferably at — 196° (liquid nitrogen). It may be handled by normal vacuum-line techniques in clean glassware but is decomposed readily by water and protonic acids. 

Broken glassware, which may be contaminated, must be picked up only by using mechanical means such as tongs, brush and dust pan, or forceps—never with bare or gloved hands. Contaminated reusable items, such as sharps, may not be stored or processed in a way that requires employees to reach into containers where the contents cannot be seen or safely handled. 

Air-free glassware wiihl4/20 standard tapered joints arc used throughout. Both Fe3(CO)i2 and [PPN]2[Fe3(CO)ii] can be handled briefly in air as solids if a glove box is not available, but must be stored under nitrogen. The reaction can easily be scaled up or down. 

Handle and store laboratory glassware with care to avoid damage do not use damaged glassware. Use extra care with Dewar flasks and other evacuated or pressurized glass apparatus shield or wrap them to contain chemicals and fragments should implosion occur. 

---