Abstract: A method of manufacturing a compound of general formula (R3—C)2P—L1—X—L2—P—(C—R3)2, in which each R is independently a pendant, optionally substituted, organic group through which the group is linked to tertiary carbon atom C; L1, L2 are independently a linking group selected from an optionally substituted lower alkylene chain connecting the respective phosphorus atom to the group X and X is a bridging group comprising an optionally substituted aryl moiety to which the phosphorus atoms are linked on available adjacent carbon atoms, comprises: i) reacting together a compound of formula H—L1—X—L2—H with an organometallic compound to form an intermediate compound of formula M—L1—X—L2—M, where M is an alkali metal atom; ii) reacting said intermediate compound with a compound of formula (R3—C)2P—A, where A is a halogen atom, to form said compound of general formula (R3—C)2P—L1—X—L2—P&

Abstract: A device for providing protection against the debris produced by a bolt that can be cut by a pyro bolt cutter, in particular through the use of a pyrotechnic device, the device including a confinement enclosure which surrounds the body of the bolt where it leaves the cutting device, and including resiliently deformable members such as membranes that are slit in their centers, with the body of the bolt passing in a substantially sealed manner through the centers of the membranes. The device serves to trap inside the confinement enclosure the debris that are produced when the bolt is cut, and it is particularly applicable to the aerospace industry.