Four novel metal–organic frameworks, [Cu(Tmp)2(H2O)] · NO3 (I) (Tmp = 3,4,7,8-tetramethyl-1,10-phenanthroline), [Mn(Tmp)2(H2O)2] · 2NO3 · H2O (II), [Pb(Tmp)(CH3COO)2] · 3H2O (III) and [Zn(Tmp)2(H2O)2] · 2NO3 · 2H2O (IV), have been synthesized and characterized by single crystal X-ray diffraction (CIF files CCDC nos. 88362–88365 for I–IV, respectively), IR spectroscopy, elemental analysis and thermogravimetric analysis. Both I and II complexes are crystallized in monoclinic system with space groups C2/c, P21/c, respectively, while III and IV complexes are crystallized in triclinic system with space groups \documentclass[12pt]{minimal}
\usepackage{amsmath}
\usepackage{wasysym}
\usepackage{amsfonts}
\usepackage{amssymb}
\usepackage{amsbsy}
\usepackage{mathrsfs}
\usepackage{upgreek}
\setlength{\oddsidemargin}{-69pt}
\begin{document}$$P\overline 1 $$\end{document}. Generally, these crystal structures are stabilized by O–H···O hydrogen bonds and π–π interactions between the phenanthroline rings of neighboring molecules. Thermogravimetric analyses of compounds I–IV display considerable thermal stability.