Context :

Aims : To interpret the galactic center H II region complexes as constituents of a barred galaxy ’ s nuclear star-forming ring .

Methods : We compare 18cm VLA radiocontinuumm , 8 - 22 \mu MSX IR and 2.6mm BTL and ARO12m CO emission in the inner few hundred pc .

Results : Galactic center H II regions are comparable in their IR appearance , luminosity and SED to M17 or N ! 0 , but the IR light distribution is strongly modified by extinction at 8-22 \mu , locally and overall .
In Sgr B2 at l > 0.6 ^ { o } strong radio H II regions are invisible in the IR .
In two favorable cases , extinction from individual galactic center molecular clouds is shown to have \tau \ga 1 at 8-22 \mu independent of wavelength .
The gas kinematics are mostly rotational but with systematic \pm 30 - 50 km s ^ { -1 } non-circular motion .
Sgr B and C both show the same shell and high-velocity cap structure .

Conclusions : The HII regions lie in a slightly-inclined ring of radius \approx 180 pc ( 1.2 ^ { o } ) whose near side appears at higher latitude and lower velocity and contains Sgr B. Sgr C is on the far side and both Sgr B and C represent collisions with material inflowing along the galactic dust lanes .
Sgr E is a coincidental aggregation of field objects seen tangent to the ring ’ s outer edge .
Most of the volume interior to the ring is probably devoid of dense gas and some emission seen at v=20-70 km s ^ { -1 } toward Sgr A lies outside it , in the ring