The complex orthogonal so(2,C)\mathfrak{so}(2,\mathbb C) consists of skew-symmetric 2×22\times2 matrices, with commutator bracket:

so(2,C)={X∈M2(C):XT+X=0},[X,Y]=XY−YX.\mathfrak{so}(2,\mathbb C)=\{X\in M_{2}(\mathbb C):X^T+X=0\},\qquad [X,Y]=XY-YX.

The transpose has no complex conjugation: the preserved form is complex bilinear, not Hermitian.

Dimension and structure

The independent entries above the diagonal give complex dimension 11; a basis is Eij−Eji (1≤i<j≤2)E_{ij}-E_{ji}\ (1\leq i<j\leq 2). There is one generator and its self-bracket is zero, so this algebra is abelian.

explains its general construction.

Scalar convention

This record retains C\mathbb C as its defining field. Its has twice the complex dimension; real-linear maps need not be complex-linear.