7783-42-8

colourless gas

A colourless gas, thermally stable up to red heat. Does not corrode Fe, Ni, Co, Hg, Si, Mn, B, Mg, Al or Zn below 125°C. Does not attack glass. Suffocating odour. Hydrolyzed very slowly in ice-cold water. M.p. -110.5°C, b.p. -43.7°C, tcr +88°C; d.(liq.)(—100°C) 1.780, d. (solid) (-183°C) 2.095.

Periostin (POSTN) is also called as osteoblast-specific factor 2. It is a matricellular protein, located in the alveolar walls. This gene is located on human chromosome 13q13.
Periostin was originally isolated as a osteoblast-specific factor that functions as a cell adhesion molecule for preosteoblasts and is thought to be involved in osteoblast recruitment, attachment and spreading. Additionally, periostin expression has previously been shown to be significantly increased by both transforming growth factor beta1 (TGF-beta1) and bone morphogenetic protein (BMP-2). Abnormal expression of periostin is also linked to angiogenesis and metastasis in epithelial tumors.

An iron bottle with a gas inlet tube serves as the reaction vessel. A second bottle is connected to the first to retain the unreacted HF. This is joined to a glass gas trap immersed in liquid nitrogen or a Dry Ice-acetone bath. A drying tube filled with KF is attached to exclude atmospheric moisture. The reaction vessel is filled with 500 g. of SOCl2 and 50 g of (catalyst), and anhydrous gaseous HF is introduced through the inlet tube. The HF is thoroughly absorbed, causing a mixture of SOF2 and HCl to evolve, which then is collected in the condensation trap. The reaction is so endothermic that the outside of the reaction vessel gradually becomes covered with ice. When all the SOCl2 has been consumed, more may be added without further SbCl5. Separation of the SOF2 from the HCl may be achieved either by distillation or by rapid bubbling of the gas mixture through ice-cold water, in which HCl is completely absorbed. At the same time, the SOF2 passes through with almost no decomposition. The gas is then dried over concentrated H2SO4 or over P2O5. Thionyl fluoride is stored under pressure in steel cylinders.
SOCl2 + 2 HF = SOF2 + 2 HCl

Periostin (POSTN) participates in collagen fibrillogenesis. It plays a major role in the development of scar after traumatic spinal cord injury (SCI). Periostin controls the activities of fibrocyte to stimulate myofibroblast differentiation and lung fibrosis. It modulates the amount of collagen in tissue. Periostin also participates in the assembly of the extracellular matrix (ECM) architecture.