; sel1hmbc_gs.kaf selective hmbc with gradients ; this pulse sequence is used when the selective 180 is ; less than approx 1.5 ms ; increases the sensitivity of the HMBC experiment for ; poorly resolved H resonances by as much as an order of magnitude by ; using selective proton pulses which suppress H-H J modulation. ; Spectrometer: Bruker AMX-400 with a single axis gradient ; ; set o1 on peak of interest, measure distance to coupling partner ; sel 180= (1/(distance/1.73205))/2 ; calibrate power of HL1 to give calculated sel 180 ; Bax, Farley, and Walker JMR Series A 119, 134-138 (1996) #include p2=p1*2 d0=3u d11=1m d13=4u d16=125u d27=p16/l21-2u d2=1s/(cnst2*2) ; one bond J filter 1 ze 1m dl1 2 d1 setf2|3^9 3 p1 ph1 d2 p3:d ph5 d6 p3:d ph3 d0 50u setf2^3|9 4 2u:ngrad d27 lo to 4 times l21 d16:ngrad setf2|3 p2 ph2 d13 50u setf2|9^3 5 2u:ngrad d27 lo to 5 times l21 d16:ngrad setf2|3 d0 p3:d ph4 d13 50u setf2^3 6 2u:ngrad d27 lo to 6 times l21 d16:ngrad setf2|3 go=2 ph31 d1 do wr #0 if #0 id0 zd d11 setf2^9|3 lo to 3 times td1 d11 setf2^9|3 exit ph1=0 ph2=0 0 2 2 ph3=0 2 ph4=0 0 0 0 2 2 2 2 ph5=0 ph31=0 2 0 2 2 0 2 0 ;d6 : delay for evolution of long range couplings ;d16: delay for homospoil/gradient recovery ;d27: delay for shaped gradient ;L21: loop for shaped gradients ;in0: 1/(2 * SW(X)) = DW(X) ;nd0: 2 ;NS: 2 * n ;DS: 16 ;td1: number of experiments ;MC2: QF ;use gradient ratio 5 : 3 : 4