Novel 4-fluoropyrrolidine-2-carbonyl fluoride compounds as useful fluorinated intermediates are disclosed. The transistor further comprises a diffusion blocking layer overlying the graded profile SiGe base layer, and an emitter layer overlying the diffusion blocking layer. The first metal bar is supported between the motherboard and the first daughterboard, so as to position the first daughterboard separately over the motherboard and enable the first daughterboard to be substantially perpendicular to the motherboard. A method is also provided for cutting through a pipe, chamfering the cut ends thereof and grooving the pipe.