The affinity of phosphates to zinc(II) complexes can be increased with hydrogen bond donors.
Mareque-Rivas, Juan C; Torres Martín de Rosales, Rafael; Parsons, Simon; Chemical communications (Cambridge, England)  (2004) 610–611; doi:10.1039/b314616b

data_7102499
_publ_section_title
;
 The affinity of phosphates to zinc(II) complexes can be increased with
 hydrogen bond donors.
;
_journal_issue                   5
_journal_name_full               'Chemical communications (Cambridge, England)'
_journal_page_first              610
_journal_page_last               611
_journal_paper_doi               10.1039/b314616b
_journal_year                    2004
_chemical_formula_moiety         '[(C18 H20 N6 ) Zn][NO3]2'
_chemical_formula_sum            'C18 H20 N8 O6 Zn'
_chemical_formula_weight         509.79
_space_group_IT_number           15
_symmetry_cell_setting           monoclinic
_symmetry_space_group_name_Hall  '-I 2ya'
_symmetry_space_group_name_H-M   'I 1 2/a 1'
_atom_sites_solution_hydrogens   geom
_atom_sites_solution_primary     direct
_atom_sites_solution_secondary   difmap
_audit_creation_method           SHELXL-97
_cell_angle_alpha                90.00
_cell_angle_beta                 104.670(4)
_cell_angle_gamma                90.00
_cell_formula_units_Z            8
_cell_length_a                   14.7313(12)
_cell_length_b                   13.7642(11)
_cell_length_c                   21.372(2)
_cell_measurement_reflns_used    6733
_cell_measurement_temperature    150(2)
_cell_measurement_theta_max      29
_cell_measurement_theta_min      2.5
_cell_volume                     4192.1(6)
_computing_structure_refinement  'SHELXL-97 (Sheldrick, 1997)'
_computing_structure_solution    'SHELXS-97 (Sheldrick, 1990)'
_diffrn_ambient_temperature      150(2)
_diffrn_measured_fraction_theta_full 0.940
_diffrn_measured_fraction_theta_max 0.940
_diffrn_measurement_device_type  'Bruker Smart Apex ccd'
_diffrn_measurement_method       Omega
_diffrn_radiation_monochromator  graphite
_diffrn_radiation_source         'fine-focus sealed tube'
_diffrn_radiation_type           MoK\a
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_diffrn_reflns_av_sigmaI/netI    0.0326
_diffrn_reflns_limit_h_max       18
_diffrn_reflns_limit_h_min       -19
_diffrn_reflns_limit_k_max       18
_diffrn_reflns_limit_k_min       0
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_diffrn_reflns_theta_max         28.83
_diffrn_reflns_theta_min         1.78
_exptl_absorpt_coefficient_mu    1.227
_exptl_absorpt_correction_T_max  1
_exptl_absorpt_correction_T_min  0.758
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details   Sadabs
_exptl_crystal_colour            colourless
_exptl_crystal_density_diffrn    1.615
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       block
_exptl_crystal_F_000             2096
_exptl_crystal_size_max          0.50
_exptl_crystal_size_mid          0.50
_exptl_crystal_size_min          0.33
_refine_diff_density_max         1.997
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_refine_diff_density_rms         0.111
_refine_ls_extinction_method     none
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_refine_ls_hydrogen_treatment    mixed
_refine_ls_matrix_type           full
_refine_ls_number_parameters     314
_refine_ls_number_reflns         5146
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_refine_ls_restrained_S_all      1.080
_refine_ls_R_factor_all          0.0512
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_refine_ls_shift/su_mean         0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'calc w=1/[\s^2^(Fo^2^)+(0.0683P)^2^+12.1090P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1251
_refine_ls_wR_factor_ref         0.1275
_reflns_number_gt                4752
_reflns_number_total             5146
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            b314616b.txt
_cod_data_source_block           RR175A
_cod_depositor_comments
;
The following automatic conversions were performed:
'_exptl_absorpt_correction_type' value 'Multiscan' changed to 'multi-scan'
according to '/home/saulius/struct/CIF-dictionaries/cif_core.dic'
dictionary named 'cif_core.dic' version 2.4.1 from 2010-06-29.

Automatic conversion script
Id: cif_fix_enum 1527 2010-12-29 10:47:43Z saulius 

The following automatic conversions were performed:

'_symmetry_cell_setting' tag value 'Monclinic' was replaced with
'monoclinic' value.

Automatic conversion script
Id: cif_fix_values 1646 2011-03-28 12:23:43Z adriana 
;
_cod_original_sg_symbol_H-M      I2/a
_cod_database_code               7102499