  Following the detection of CO and HCN in Pluto's atmosphere, we report on new
ALMA observations of Pluto with two main goals: (i) obtaining
spatially-resolved measurements (~0.06'' on the ~0.15'' disk subtended by Pluto
and its atmosphere) of CO(3-2) and HCN(4-3) (ii) targetting new chemical
compounds, primarily hydrogen isocyanide (HNC). The CO line shows an absorption
core at beam positions within Pluto's disk, a direct signature of Pluto's cold
mesosphere. Analysis provides tentative evidence for a non-uniform temperature
field in the lower atmosphere (near 30 km), with summer pole latitudes being
7$\pm$3.5 K warmer than low latitudes. This unexpected result may point to
shorter radiative timescales in the atmosphere than previously thought. The HCN
emission is considerably more extended than CO, peaking at radial distances
beyond Pluto limb, and providing a new method to determine Pluto's HCN vertical
profile in 2017. The mean (column-averaged) location of HCN is at 690+/-75 km
altitude, with an upper atmosphere (> 800 km) mixing ratio of ~ 1.8 x
10$^{-4}$. Little or no HCN (<5 x 10$^{-9}$ at 65 km) is present in the lower
atmosphere, implying undersaturation of HCN there. The HCN emission appears
enhanced above the low-latitude limb, but interpretation, in terms of an
enhanced HCN abundance or a warmer upper atmosphere there, is uncertain. The
first detection of HNC is reported, with a (7.0$\pm$2.1) x 10$^{12}$ cm$^{-2}$
column density, referred to Pluto surface, and a HNC / HCN ratio of
0.095+/-0.026, very similar to their values in Titan's atmosphere. We also
obtain upper limits on CH3CN (< 2.6 x 10$^{13}$ cm$^{-2}$) and CH$_3$CCH (< 8.5
x 10$^{14}$ cm$^{-2}$); the latter value is inconsistent with the reported
detection of CH$_3$CCH from New Horizons. These upper limits also point to
incomplete resublimation of ice-coated aerosols in the lower atmosphere.
