My recommendation to the OP (from my comment) was to use NVD3. The code for tooltipContent
is from the OP.
p1 <- nPlot("x", "y", data = data, type = 'scatterChart')
p1$chart(tooltipContent = "#! function(key, x, y, e){
return 'tip: ' + e.point.interakcja
} !#")