Self-assembled Transition Metal Coordination Frameworks of ...

i ____ 3+ i --—-
C 0pper(H)
2+
complexes
” I K | / ' N‘/j
. \ H""'_C~.-""N\ N’ w/A ‘nu 0 S \ ~. N\ \", | . Cu / .°"2 ­
ii l l \ ll Y
CI I 0 I /"*~~ 5 8 .--"ORQ 0/23""
Cl H |10'"’S/f “ "" H: \ A “"'"/\‘;
T *:'\ I /
T ifi / Scheme 4.4. The tentative structures of Cuw carbohydrazone complexes lTfleft)
and 14 (right).
\ / I l / N \N_ \ l / I ii’/’N ea". \N
2
N‘.
N...
| Ion,
\)%,\ N |N : /
|/
. 2% Zku.“
\/\
\N__,_,..-'—"(E:U...__N/X
/1 -4 0 N/’
Scale 4.5. The tentative structures of Cu(II) carbohydrazone complexes 16 (left)
and 17 (right).
4.3.1. MALDI MS spectral features
The MALDI MS spectra of Cu(II) complexes show some similar features and
are different from stable molecular square grid complexes. Though molecular ions
could not be observed for all compounds, sensible fragments were observed. This was
not surprising as the structure and stability of coordination complexes under ionization
conditions are dependent on various factors like the ligand itself, metal ions, counter
ions, solvent, temperature, concentration, etc. However, the [Cu(HL)]+ fragment was
readily observed in all cases. MALDI mass spectra of all the complexes were taken in
CHQCIQ as DCTB mix on positive ion mode. The application of MALDI to cluster
l35