Welcome to how City Planners in real life (and Central Governments too) have to deal with such questions as your unemployment issue.
The guys above have made valid points, but I'll try and give some different angles of attack.
The Moose is right there with transit options for within in the city tile itself. Some heavy rail, monorail, bus stops all coupled with Park and Ride facilities could make your transit system more efficient and accessible between residents and jobs. You could go down the asphalt path and maybe have a crack and some road upgrades, upgrades to avenues or one-way streets, or even go the whole hog and build express or motorways (highways) to give better connections between jobs and residents. I have also noted you have inter-connected city tiles which means efficient and readily available neighbour-tile access by road, highway, rail, mono rail or even (no wont suggest Ferry) need to be in place to allow inter-tile commuting which can spur things along including making no-job lots disappear.
If you want to try something non transit, tinker with taxes to slow down demand of one type, or increase demand of another. But beware for the unwise it can play havoc with one's finances if they are not careful. And remember your parks, plaza's and green spaces to help increase desirability which brings in more wealthier sims and more substantial developments. Oh and do not forget pollution.
All these are the options you have in combating unemployment that I use to keep unemployment down
Oh one last thing, mix your zoning variety and do not be afraid to mix and match residential and commercial zones together too - it makes for interesting development and as for my biggest city tile of 1.3 million - I get a "walking city"