Bystander assistance

Using literature data, bystander assistance factors, B[Y], could be calculated for a number of substituents. For example, the thermolysis of certain ketone tosylhydrazone salts afforded dialkylcarbenes which gave competitive 1,2-H shifts, Eq. 23, where either Ha or Hb migrated. 

The product ratio a /b (statistically corrected for the number of competing H migrants), gives the relative migration rate of Ha vs. Hb, or k /kub- The rate constant for the migration of Ha corresponds to the intrinsic migratory aptitude of Ha (M[H]) multiplied by the bystander assistance factor for Y, B[Y], The carbon atom that bears Hb has no bystander substituent, so that km, is simply A/[H], We thus obtain Eq. 24. 

Both Af[H]s cancel, so that the bystander assistance factor, B[Y], for any substituent, Y, is simply the corrected product ratio a /b. 8 In Eqs. 23 and 24, bystanders Y were found to enhance H-shifts in the order MeO > alkyl > Ph quantitative data appear in Table 3.8... 

Table 3. Bystander Assistance Factors for Hydrogen Migration in Dialkylcarbenes°...

A. Nickon, New Perspectives on Carbene Rearrangements Migratory Aptitudes, Bystander Assistance, and Geminal Efficiency, Acc. Chem. Res. 1993, 26, 84. 

Using this type of evaluation, Nickon (1993) calculated the bystander assistance factors B[X] given in Table 8-1 for aprotic Bamford-Stevens reactions at 150 10°C (experimental data from various sources). 

Table 8-1. Some bystander assistance factors for hydrogen migration in thermally generated carbenes of type 8.43-8.44 (after Nickon, 1993).

Another view of the Si(lOO) etching mechanism has been proposed recently [28], Calculations have revealed that the most important step may actually be the escape of the bystander silicon atom, rather than SiBr2 desorption. In this way, the SiBr2 becomes trapped in a state that otherwise has a very short lifetime, pennitting many more desorption attempts. Prelimmary results suggest that indeed this vacancy-assisted desorption is the key step to etching Si(lOO) with Br2. 

Gather important information the agent used was it aerosol, liquid, gas, powder or vapor location method of delivery do you have the necessary personal protective equipment (PPE) to deal with the hazard, or have you called for assistance by a specialized team are you sure that anyone who enters a contaminated area has the proper PPE and is trained in its use be sure to establish control — keep all victims, non-victims and bystanders at the crime scene (if there is any suspicion of an attack) until it is determined who among them may be a terrorist or a witness perform decontamination, triage if necessary, isolation, quarantine, search and locate evidence, maintain chain of control, and collect samples. 

The militsiya were busy calming bystanders, helping them up and herding them on. A handful of Bugayev s men were assisting them, but most of the rest stood close by. Not many of the militsiya bothered to look over their shoulders at what was going on in the road. Until this unseemly mess was mopped up, the road was exclusively Bugayev s province. 

Acknowledgment Thank you to Vickie Carson at the Mammoth Cave National Park for sourcing the CCC photographs used in this chapter, and to Geoff Ceimpbell and the folks at Innocent Bystanders and HotAir.com for their assistance with Figure 62.4. Big thanks to Sue Roberts for discussing with me some of the ideas in this chapter (errors and omissions are mine). 

Would you assume personal responsibility and respond Surely the bystanders in the Kitty Genovese and Deletha Word incidents described earlier noticed the event and interpreted it as requiring assistance. Steps 1 and 2 of Latan6 and Darley s decision model were likely satisfied. The breakdown probably occurred at Step 3—perceiving personal responsibility. 

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