On his first day in office in 2011, Chicago Mayor Rahm Emanuel signed an executive order saying he wouldn’t accept campaign donations from contractors doing business with the city.

But taking money from employees of those contractors? A different story by Emanuel’s standards.

Emanuel banked $18,100 last December from attorneys at Sidley Austin LLP – six months after the Chicago law firm started working for the city on a heater case involving the Chicago Police Department.

To be clear, the firm hasn’t given Emanuel a penny. But the firm’s attorneys have been awfully good to the mayor.

In all, they donated $57,100 to Emanuel’s campaign fund since late 2010, shortly after he announced he was running for mayor. Just over a third of that total, or $21,100, arrived after the city hired Sidley Austin.

By far the most generous has been Howard Trienens, a Sidley Austin partner and the firm’s former chairman, who has personally donated $30,300 to “Chicago for Rahm Emanuel,” according to data from the Illinois State Board of Elections.

Trienens says he and other attorneys give to Emanuel because they like him – city business isn’t why they whipped out their checkbooks.

As for the executive order, a city spokeswoman stresses that Emanuel didn’t break any rules by accepting the cash last December.

“The Executive Order does not prohibit employees of city vendors from contributing,” she says in an email. “Rather, it prohibits owners of city vendors, defined as those who own at least 7.5 percent of the firm, from contributing.”

The BGA asked whether Emanuel would consider broadening the order to include employees of city vendors, too – plugging what’s a pretty sizable loophole.

“I won’t have a comment for you on this,” the spokeswoman says.

Last June the city hired Sidley Austin to probe misconduct allegations against retired Chicago police detective Reynaldo Guevara.

According to the Sun-Times and other news outlets, Guevara has been accused of beating and intimidating suspects and witnesses, and providing authorities with false translations of interviews with Spanish speakers.

The BGA recently reported that Chicago has spent $521.3 million for police misconduct-related claims over the past decade. That figure didn’t include bills related to the Guevara probe, which appears to be the first piece of city business for Sidley Austin in at least a decade.

The city has paid Sidley Austin nearly $560,000 since last year, records show. The review is still ongoing – meaning the tab could climb even higher.

Leading the investigation is ex-U.S. Attorney and current Sidley Austin partner Scott Lassar.

David Hoffman, the city’s former inspector general, also is a partner at the firm (as well as a BGA board member). Hoffman endorsed Emanuel for mayor in February 2011, shortly before Hoffman joined Sidley Austin.

But that support had nothing to do with the city’s decision, the city spokeswoman says, adding Corporation Counsel Stephen Patton picked Sidley Austin because of Lassar’s “reputation for independence and thoroughness.”

“The mayor had no involvement in the decision,” she adds.

Hoffman did not return phone calls.

Lassar was among the attorneys who donated to Emanuel last December, chipping in $1,000 as part of a fundraiser for the mayor. Sidley Austin attorneys attended the event, but officials said the firm did not host it.

Lassar declined to comment for this story, as did Carter Phillips, chairman of Sidley Austin’s executive committee.

Emanuel’s campaign fund had $7.4 million on hand at the end of March, according to the state elections board.

Curious Timing With Developer Donations

Speaking of campaign donations, money has been flowing to the mayor from employees of a real estate company that controls a prominent development site at Peshtigo Court and Grand Avenue, just west of Navy Pier in Streeterville.

Chicago-based Related Midwest LLC and city officials met in December to discuss the parcel but the company hasn’t submitted a development plan to the Emanuel administration as of yet.

The site is zoned for a structure with up to 232 residential units. Related Midwest would need a zoning change to put up something larger.

It’s unclear what the company’s plans are, though it tapped New York architect Robert A.M. Stern to design a building for the site, according to the architectural firm.

In the meantime, employees of Related Midwest and its New York-based parent company – eight people in total – donated $28,100 to Emanuel’s campaign fund in March, according to the state board of elections.

Why are they feeling so generous?

A Related Midwest spokeswoman wouldn’t say, and the Emanuel spokeswoman wouldn’t speculate.

“I don’t know that we have anything to say about something that hasn’t happened,” she says.

This column — a new regular feature called The Public Eye, appearing on the Chicago Sun-Times’ political portal Early & Often – was written and reported by the Better Government Association’s Andrew Schroedter, who can be reached at (312) 821-9035 or aschroedter@bettergov.org.